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Book. (\ h 

Copyright N" . 



COPYRIGHT DEPOSIT. 



HOT WATER 
FOR 
DOMESTIC USE 



A Complete Guide to the Methods of Supplying and 

Heating Water for Domestic Purposes, giving 

each step to be taken and explaining 

why it is done. 



J 



Eldited by 

no. K. Allen 



Member of American Society of Inspectors of 
Plumbing and Sanitary Engineers; Member 
Royal Sanitary Institute of Great Britain; 
Associate Member American Society of 
Heating and Ventilating Engineers. 



Price 50 Cents 



DOMESTIC ENGINEERING CO. 

323-325 Dearborn Street 

Chicago 

1910 






Copyright 

Domestic Engineerins Co. 

1910 



% 



CCI.A2S0867 



CONTENTS. 

Circulation of Hot Water 7 

Heat and Temperature 10 

Sensible and Latent Heat 13 

Conduction of Heat 18 

Range Boiler Connections 24 

Use of Check and Safety Valves 33 

Check Valves for Cold Water Supply 38 

Boiling Points of Water 40 

Pressure of Water 43 

Heating Water by Kitchen Ranges 49 

Incrustation of Water Backs 52 

Deposits of Mud in Water Backs and 

Boilers 60 

Heating Water by Pipe Coils 62 

Special Water Heaters 64 

Garbage Burning Water Heaters 67 

Heating Water with Gas 68 

Instantaneous Water Heaters 70 

Gas Supply to Water Heaters 78 

Gas Heaters Must be Vented 79 



Special Gas Water Heaters 81 

Multiple Gas Water Heaters 86 

Automatic Instantaneous Water Heaters. 88 

Use of Steam for Heating Water 96 

Steam Connections to Range Boilers .... 101 

Heating Water with Live Steam 104 

Heating Water with Exhaust Steam 107 

Heating Water with Steam in Contact 110 

Heating Water with Steam Nozzles 117 

Index 1 19 



HOT WATER FOR 
DOMESTIC USE 



Circulation of Hot Water, 
underlying principles. 

To thoroughly understand how water can be 
heated and distributed throughout a building in 
pipes, so that upon opening a faucet a plentiful sup- 
ply of hot water can be obtained at all fixtures, it 
is first necessary to understand the principles which 
underHe the heating of water for domestic use; to 
be familiar with the properties of hot water, and 
understand the behavior of water when subjected 
to heat or cold. 

It is a well-known property of water, that, at 
ordinary temperatures, when subjected to heat it 
will expand; consequently if a certain quantity of 
water, which at a low temperature would just fill 
a measure, be heated, part of the liquid will over- 
flow from the measure, and while the measure would 
still remain full, the weight of the liquid would be 
less than before heat was applied. Quantity of 
water must not be confused with unit measure of 
water. For instance, if a gallon of water be put 
in a vessel large enough to contain more than a 
gallon, and the water be heated, the quantity of 
water at the new temperature will weigh exactly 



8 Hot Water for Domestic Use 

the same as it did before being heated, but there 
will be a greater quantity of water in the vessel, 
and if from that greater quantity of water, one 
gallon be measured out it will weigh less than the 
gallon of water originally put in the vessel. In 
other words, heating water increases its bulk but 
decreases its weight per unit measure, while con- 
versely, cooling of water decreases its bulk but in- 
creases its weight per unit measure. 

The foregoing statement is the rule, but there 
is an exception to the rule. When water has a 
temperature of 39° Fahrenheit it is at its maximum 
density, and the application of either heat or cold 
will then cause it to increase its bulk. 

Cause of Water Circulation. 
It is due to this difference in weight between two 
equal volumes of water at different temperatures, 
that circulation takes place, and makes possible the 
heating of a large tank or body of water by apply- 
ing heat at only one point. 

Lx)CAL Circulation of Water. 
Local circulation of water, or the circulation of 
water within an open vessel or tank, will be better 
understood by a reference to Fig. i. If heat be 
applied to the center of the tank, as shown in the 
illustration, the water immediately above where the 
heat is applied, will become warmer, increase in bulk 
and decrease correspondingly in weight and will 



Circulation of Water 9 

be displaced by a coI3er and heavier column of 
water, flowing down around the sides of the ves- 
sel to the bottom. As the heated water from the 
bottom of the tank rises to the surface it comes in 
contact with colder water and air to which it im- 




Fig. 1. 

parts some of its heat. The constant rising of 
water near the center of the vessel forces the water 
to the sides and in passing down along the walls 
of the vessel the water parts with more heat until, 
having arrived at the point where it has the lowest 



10 Hot Water for Domestic Use 

temperature of any water in the tank, it again is 
brought to the center immediately above the flame 
to displace the heated water, and so in turn again 
makes the circuit. This constant traveling of water 
from the bottom of a tank and back again is known 
as local circulation and it is due to this circulation 
that we are able to heat water in a vessel. If in- 
stead of applying heat to the bottom of the tank it 
were applied to the surface of the water, no cir- 
culation would take place, and outside of the upper- 
most layers the temperature of the water within 
the vessel, would not be raised. 

Heat and Temperature. 

The terms heat and temperature should not be 
confused. Heat has reference to the quantity of 
heat required by a body to raise its temperature. 
Heat is commonly accepted as a form of energy, a 
vibration or wave motion of the molecules com- 
posing matter. According to the generally ac- 
cepted theory, the molecules that compose matter 
are in a constant state of unrest which keeps them 
moving back and forth, or vibrating with a greater 
or less velocity. It is this movement of the mole- 
cules which is generally believed to cause the sensa- 
tion of warmth and cold ; when the motion is slow, 
the matter feels cold, whereas when the motion is 
rapid, the body feels warm. 

Heat not being a substance cannot be measured 
by any of the usual weights or measures, but as it 



British Thermal Unit 11 

produces certain effects it can be measured by the 
effects it produces. It is obvious that if two balls 
of metal of different sizes are heated to the same 
temperature, that one ball, the larger one, will 
require more heat than did the smaller one. Again, 
suppose that it takes a certain amount of heat to 
raise the temperature of one pound of water one 
degree Fahrenheit, then it would take just double 
that amount of heat to raise two pounds of water 
one degree Fahrenheit, and three times the amount 
of heat to raise three pounds of water one degree 
Fahrenheit. Further, if it takes a certain amount 
of heat to raise one pound of water one degree, it 
would take twice that quantity of heat to raise the 
same quantity of water two degrees Fahrenheit, 
and three times the amount of heat to raise the tem- 
perature of the water three degrees Fahrenheit. 
Unit of Heat. 

It follows from the foregoing explanation that 
there is some unit by which heat can be measured. 
This unit is known as a British Thermal unit, which 
is usually abbreviated to B. T. U. A British Ther- 
mal Unit is the quantity of heat required to raise 
the temperature of a pound of water from 62° to 
63° Fahrenheit. In practice, however, a B. T. U. 
is assumed to be the quantity of heat required to 
raise one pound of water one degree Fahrenheit. 

It might be well to point out here that, as a mat- 
ter of fact, it requires slightly more than one 



12 Hot Water for Domestic Use 

British Thermal Unit to produce a change of one 
degree in one pound of water for temperatures 
over 63° Fahrenheit, the difference increasing the 
further the temperature rises above 63°. For tem- 
peratures below 62°, it takes slightly less than one 
British Thermal Unit to produce a change of 1° 
Fahrenheit in one pound of water, and conversely 
to the others the difference is greater the more the 
temperature falls below 63°. 

From what has been stated it will be seen that it 
takes more heat to raise the temperature of one 
pound of water from 80° to 81° Fahrenheit than it 
will to raise one pound of water from 40° to 41° 
Fahrenheit, and conversely, it will take less heat to 
raise the temperature of one pound of water from 
40"^ to 41'' Fahrenheit than it will to raise it from 
41° to 42° Fahrenheit. Nothwithstanding this 
fact, the difference between the amount of heat 
actually required and the British Thermal Unit 
commonly used in practice is so slight that it is 
entirely ignored. 

The term temperature is used to denote the sensa- 
tion of cold or warmth, which is sensible to the 
touch or is indicated by a thermometer. For in- 
stance, if a body be heated and held near the hand, 
a feeling of warmth is experienced. If it be ap- 
proached to the bulb of a thermometer the mercury 
will rise in the stem, thus indicating heat. If the 



Forms of Heat 13 

body be now removed and the heat withdrawn, a 
feeling of cold is experienced when brought in con- 
tact with the hand, and if approached to the bulb 
of a thermometer, the mercury will drop in the 
stem. 

Sensible Heat. 

There are two kinds of heat, known respectively 
as sensible heat and as latent heat. The heat which 
is sensible to the touch, or that can be indicated by 
a thermometer is known as sensible heat. The 
more sensible heat a body possesses, the hotter it 
is, and the higher its temperature; the less sensible 
heat it has, the colder will be the body, and the 
lower its temperature. 

Temperature is not a measure of the quantity of 
heat a body possesses but may be considered to be 
a measure of the velocity with which the molecules 
of matter vibrate to and fro. A small vessel of 
water might be heated very hot and yet not possess 
as much heat as a larger vessel of water which is 
only warm to the touch. 

Latent Heat. 

If steam at atmospheric pressure has its temper- 
ature taken by a thermometer, it will be found that 
the mercury indicates 212'' Fahrenheit. If the 
steam be now permitted to condense, and the tem- 
perature of the water is taken, it will be found to be 



14 Hot Water for Domestic Use 

of the same temperature as the steam, or 212° 
Fahrenheit. In condensing the steam into water, 
however, heat has been given off to the atmosphere 
and to surrounding objects; clearly then, the steam 
before condensation possessed some heat which was 
not sensible to the thermometer. This is true, and 
this insensible heat is known in practice as latent 
heat. 

Again, take a block of ice which has a tempera- 
ture of 32° Fahrenheit, and let it melt in a closed 
box or compartment, watching meanwhile a ther- 
mometer in the box or compartment. It will be 
found that the air of the compartment and the walls 
have been lowered in temperature, as the ice melts, 
but the temperature of the ice, also the temperature 
of the water remain constant at 32° Fahrenheit. It 
is evident then that when water passes into a solid 
state it requires latent heat to freeze it, and that 
this latent heat is given off in the process of melt- 
ing. Likewise, when water passes from the liquid 
to the gaseous or vapor state it is with an absorp- 
tion of heat that remains latent but which is given 
off when the steam returns to the liquid state. 

Circulation in Circuit. 

Instead of circulating locally in a vessel, water 

can be made to travel continuously through a 

loop or circuit and back to the point of place of 

starting. The principle of circulation in circuit 



A Simple Experiment 



15 



is shown in Fig. 2. If a U-shaped tube be filled 
with water up to the top of the dotted line a, the 
water will stand in both legs of the loop at ex- 
actly the same height. This is due to the fact 
that the water in both 
the legs, being of the 
same temperature and 
density, will exactly bal- 
ance each other and re- 
main so in obedience to 
the law that water at rest 
will find its own level. If, 
on the other hand, the 
tube be connected near 
the top by the cross-tube 
shown by dotted lines, 
the water would finds its 
level at the highest point 
to which it could raise, 
and would remain sta- 
tionary at that point, and 
so long as the temperature of the water at all points 
remained unchanged, there would be no perceptible 
movement of the water within the tube. Should, 
however, a U-shaped tube, such as shown in the 
illustration, be filled w^ith water up to the line a, 
and there be no cross-tube connecting the tops of 
the two legs, and further, should heat be applied 




Fig. 2. 



16 Hot Water for Domestic Use 

to one of the legs, as at b, the water in that leg 
would become warmer, increase in bulk, and would 
rise above the level of the line a. It would simply 
be a case of two columns of liquid of different den- 
sities, and a greater column of the lighter liquid 
would be required to balance the heavier liquid. 

That portion of the lighter liquid which rises 
above the line of the heavier liquid, if it had no 
bounds to confine it, it could flow in any direction ; 
so that if a tube, represented by the dotted lines, 
were to join the two legs of the U-shaped tube, the 
excess water in the hot water side would flow to 
the cold water side of the loop. This transfer of 
water from the hot water to the cold water side 
of the loop would upset the balance of the two col- 
umns of water and water would flow from the cold 
water side to the hot water side to replace the loss 
of weight, thus establishing a circulation in the di- 
rection of the arrows, which would continue as long 
as heat was applied. 
Velocity of Flow of Hot Water in Circulation. 

The velocity of flow of water circulating through 
a loop depends on the height of the loop, the differ- 
ence between the temperatures of the two columns 
of water, and the frictional resistance offered to the 
flow of water. It is obvious that if there is a dif- 
ference in weight of one ounce between two col- 
umns of water two feet high, that if the columns 
were 20 feet high, there would be a difference of 



Resistances to Flow 17 

loxi ounce, equals lo oimces pressure, tending to 
move the water along. 

As the hotter water becomes, the more it in- 
creases in bulk and the lighter per unit of bulk it 
becomes, it would naturally follow that the hotter 
the water was in one leg of the loop, and the colder 
in the other leg, the greater would be the differ- 
ence between the weights of the two columns, and 
the greater would be the pressure-head, tending to 
move the water through the circuit. Where rapid 
circulation through a high loop is required, there- 
fore the velocity can be increased by covering the 
flow pipe with some good non-conducting material 
and leaving the return pipe uncovered so that radi- 
ation can take place from the surface of the pipe, 
thus lowering the temperature of the water within. 

The flow of water through a pipe is impeded by 
the frictional resistance offered by the walls of the 
pipe. Naturally, the frictional resistance will vary 
with the roughness of the inside of the pipe, and the 
number of bends, branches, and projections. Where 
circulation is inclined to be sluggish, therefore, the 
resistance offered to the flow can be materially re- 
duced by using long turn fittings, or making pipe 
bends where the direction of the pipe is changed, 
and by reaming the ends of all pipes screwed into 
fittings, to remove the burr formed by the wheel 
when cutting the pipe. Lead pipe having no coup- 



18 Hot Water for Domestic Use 

lings or fittings and presenting a smooth flush in- 
terior water-way oflfers the least resistance of any 
kind of pipe to the flow of water. Where wrought- 
iron pipe is used, however, the frictional resistance 
can be greatly reduced by using recessed drainage 
fittings. These fittings are recessed so the pipe, 
when screwed into place, finishes flush on the in- 
side without recess or projection. 

Conduction of Heat. 

In the experiments explained in relation to Figs. 
I and 2, the heat was not applied direct to the 
water, but to the vessel in which the water was con- 
tained. It is quite obvious then that heat had to be 
transmitted through this containing vessel before it 
could be absorbed by the water. The passage of 
heat through an iron vessel in the manner described 
is due to conduction of heat. Garnot, in his 
"Physics," explains the phenomena of conduction, 
as follows: "A hot body is one whose molecules 
are in a state of vibration. The higher the temper- 
ature of a body, the more rapid are these vibrations, 
and a diminution in temperature is but a dimin- 
ished rapidity of the vibrations of the molecules. 
The propagation of heat through a bar is due to a 
gradual communication of this vibratory motion 
from the heated part to the rest of the bar. A good 
conductor is one which readily takes up and trans- 
mits the vibratory motion from molecule to mole- 



Conduction of Heat 19 

cule, while a bad conductor is one which takes up 
and transmits the motion with difficulty. But even 
though the best of conductors the propagation of 
this motion is comparatively slow. How, then, can 
be explained the instantaneous perception of heat 
when a screen is removed from a fire or when a 
cloud drifts from the face of the sun ? In this case, 
the heat passes from one body to another without 
aflfecting the temperature of the medium which 
transmits it. In order to explain these phenomena, 
it is imagined that all space, the space between the 
planets and the stars, as well as the interstices of 
the hardest crystal, in short, matter of any kind, is 
permeated by a medium having the properties of 
matter of infinite tensity, called ether. The mole- 
cules of a heated body, being in a state of intensely 
rapid vibration, communicate their motion to the 
ether around them, throwing it into a system of 
waves, which travel through space and pass from 
one body to another with the velocity of light. When 
the undulations of the ether reach a given body, the 
motion is given up to the molecules of that body, 
which, in their turn, begin to vibrate; that is, the 
body becomes heated. This motion of the waves 
through the ether is termed radiation, and what is 
called a ray of heat, is merely a series of waves 
moving in a given direction.*' 

A familiar example of conduction can be men- 
tioned in the case of an iron bar, one end of which 



20 Hot Water for Domestic Use 

is thrust into a fire, even though the rest of the bar 
be screened from the flames so the rays cannot fall 
on it, in a short time the bar will become warm, 
then hot from the heat which had crept along from 
the end that is heated. Another example is the 
case of a vessel of water, or other fluid, heated by 
placing the vessel on top of a stove. 

Thermometers. 
Thermometers made for measuring ordinary tem- 
perature, such as obtain in hot water installations, 
consist of a small glass tube at one end of which 
is a bulb filled with mercury. This tube is mounted 
on a background or support, which is divided up 
into a scale showing the various degrees of temper- 
ature. The Fahrenheit thermometer, which is the 
one generally used in practice, is graduated by find- 
ing the point where the mercury stands in the tube 
when the instrument is placed in melting ice, and 
marking this point 32''. The point where the 
mercury stands when the instrument is immersed 
in water boiling in an open vessel at sea level is 
then found and marked 212°. The space between 
these two points is then divided into 180 equal 
parts, each of which represents one degree Fahren- 
heit of temperature. 

Conducting Properties of Materials. 
The conducting properties of various materials is 
of interest in domestic water heating, for two sep- 



Conductivity of Materials 21 

arate reasons. First, to find a good conductor of 
heat; and, second, to know a poor conductor of 
heat. All known substances will conduct heat to a 
certain extent, but the rapidity of the conduction 
varies with different substances, some of these ma- 
terials conduct heat very rapidly, while others con- 
duct heat very slowly, and according to the rapidity 
with which they conduct heat, the various sub- 
stances are known as good conductors and as bad 
conductors. 

It can clearly be seen that a material which is a 
good conductor of heat would make a good material 
for water backs, and water heaters, if in other ways 
suitable for the purpose. Of course, a material 
which is very expensive would not be used for such 
a purpose, no matter how suitable it might be in 
other ways, and a material like tin, zinc or lead 
would not be suitable, on account of their low fus- 
ing points, even though they possessed high con- 
ductivity. The relative conducting powers of vari- 
ous metals and alloys based on silver, which is con- 
sidered as I, can be found in Table I. 
Table I. 
Heat Conductivity of Metals and Alloys. 

Relative 
Conductivity. 
170 
.200 
.150 
.085 

It will be noticed from the table that there is a 
wide range of difference between the conductive 





Relative 




Metal. 


Conductivity. 


Metal. 


Silver, 


1.000 


Cast Iron, 


Copper, 


.770 


Zinc, 


Bras?, 


.330 


Tin, 


Steel, 


.120 


Lead, 



22 Hot Water for Domestic Use 

powers of the various metals and alloys and that 
copper has the highest power of conductivity of any 
of the substances enumerated which are suitable for 
plumbing materials. 

TABLE OF RELATIVE VALUE OF NON-CONDUCTING 

MATERIALS. 

Substance. Value. Substance. Value. 

Loose Wool* 3.35 Wood, across grain*. . .40 to .55 

Loose Lampblack* 1.12 Loam, dry and open 55 

Geese Feathers* 1.08 Chalk, ground, Spanish 

Felt, Hair or Wool* 1.00 White 51 

Carded cotton* 1.00 Coal ashes 35 to .49 

Charcoal, from cork 87 Gas-house carbon 47 

Mineral wool 68 to .8S Asbestos paper 47 

Fossil Meal 66 to .79 Paste of fossil meal and 

Straw R©pe, wound spirally* .77 asbestos 47 

Rice Chaff, Loose* .76 Asbestos, fibrous 36 

Carbonate Magnesia.. .67 to .76 Plaster of Paris, dry 34 

Charcoal from wood*. .63 to .75 Clay with vegetable fibre... .34 

Paper* 30 to .74 Anthracite coal, powdered*. .29 

Cork* 71 Coke, in lumps* 27 

Sawdust* 61 to .68 Air space, undivided. .12 to .22 

Paste of Fossil Meal and Sand 17 

Hair 63 Baked clay, brick 07 

Wood ashes 61 Glass 05 

Stone 02 

* Combustible and sometimes dangerous. 

It often is desirable to cover hot water pipes to 
keep them from radiating heat, or to prevent them 
from becoming frozen. Further, a covering ma- 
terial is sometimes desired to prevent pipes from 
sweating during warm weather. Not only is it de- 
sirable to cover water pipes, but under some condi- 
tions hot water tanks and even the heaters must be 



Range Water Backs 



23 



protected from the atmosphere, and the question 
then is to find a suitable material of low conduc- 
tivity instead of one of high conductivity. A table 
showing the relative value of non-conducting ma- 
terials will be found on the preceding page. 



Principle of Heating Water in a Range 

The principle by which water in a kitchen range 
boiler or hot water tank is heated from a water 

back or water heater, 
located some distance 
away, is shown by a 
reference to Fig. 3. 
In this apparatus a 
pipe is taken from the 
bottom of the tank 
and extended out a. 
short distance in a 
horizon- 




~^___jM 



Fig. 3. 



^ 



tal d i- 
recti o n, 
where 
i t ter- 
minate s 



in a return bend. From this return bend another 
pipe is extended up to and connected to the side of 
the tank, thus forming a continuous loop. If heat 
be now applied to the return bend as shown in the 



24 Hot Water for Domestic Use 

illustration, the water within will become heated, 
become lighter in volume and thus be displaced by 
a column of water of similar size within the tank. 
This movement of water, once started, will continue 
as long as heat is applied to the return bend. To 
start and maintain such a circulation, however, the 
pipe leading from the return bend to the side of the 
boiler must have a rise all of the way. Should this 
pipe become trapped in any way, the circulation of 
water would become impeded or entirely stopped, 
depending on the depth of trap, and if heat were 
applied to the return bend there would be a rat- 
tling, snapping sound that is disagreeable and alarm- 
ing, if not actually dangerous. This noise is 
caused by the generation of steam at the return bend 
and the steam, upon coming in contact with cooler 
water, after leaving the bend, becomes instantly con- 
densed, thus creating a partial vacuum, which the 
surrounding water rushes in to fill, with the re- 
sulting snapping and banging which is so annoy- 
ing. 

Range Boiler Connections. 

In Fig. 3, the return bend represents the water 
back in an ordinary kitchen range, the tank repre- 
sents the kitchen range boiler, and the pipes, the 
flow and return pipes from the boiler to the water 
back in the range, and back again, to the boiler. In 



Range Boiler Connections 



25 



Fig. 4, however, is shown the method of connect- 
ing up a kitchen range boiler, both to the water- 
back and to the 
hot and cold 
water supply 
lines. In practice 
the pipe, which 
conducts water 
from the boiler to 
the waterback, is 
known as a -How 
pipe, while the 
pipe which con- 
ducts the water 
back again from 
the waterback to 
the boiler is 
known as a return 
pipe. In an actual 
installation the 
boiler stand is on- 
ly about 1 8 inches 
high, so that the 
waterback in the 
range is at higher elevation; consequently, the 
flow pipe to the waterback must be offset, as 
shown in the illustration. It is better to make this 
offset as indicated, by bending the pipe, than to use 
elbows. Bending the pipe decreases the number of 




Fig. 4. 



26 Hot Water for Domestic Use 

joints, consequently minimizing the possibility of 
leaks ; is quicker and cheaper to install, and offering 
less resistance to the flow of water through the 
pipe. In the waterback the water is heated, flows 
through the return pipe to the boiler and passes 
to the top, where it remains on account of its less 
density than the rest of the water in the boiler. The 
coldest water is always at the bottom of a hot water 
boiler, and the hottest water is at the top. Be- 
tween these two extremes the water is graduated 
in temperature, the average temperature being found 
near the center line of the tank. 

Any emptying cock is placed on a branch to the 
flow pipe, so that the boiler can be emptied for clean- 
ing or repairs. Sometimes the boiler has an empty- 
ing pipe controlled by a valve or cock and emptying 
into the drainage system at a point lower down. 
When this method of construction is employed, it 
is the better practice to use a ground key cock, 
for if a valve be used, a slight leak in the seat of 
the valve might exist without being known, and hot 
water continually run to waste, while the point of 
loss would be hard to detect. Many authorities be- 
lieve that it is a bad practice to connect the empty- 
ing pipe from a range boiler into the house drain- 
age system, for during periods when the house is 
vacant or during temporary absence of the owner 
from home, the boiler is invariably emptied to pre- 
vent possible accident or damage from water should 



Range Boiler Connections 27 

the pipes or boiler spring a leak, either from weak- 
ened structure or bursting from frost. Under such 
conditions the emptying cock is generally left open 
and drain air from the soil, waste and vent stacks 
finds its way into the boiler and perhaps through 
hot water faucets into the house. If there is a 
sink in the building at a lower level than the boil- 
er, it is good practice to run the emptying pipe from 
the boiler to this sink, and let it discharge there, 
as would a safe waste pipe or a refrigerator water 
pipe. 

The cold water supply pipe to a kitchen range 
boiler is generally supplied with a stop cock or 
valve to shut off the water from the boiler, when 
desired. The cold water supply is connected to the 
boiler at the top, and a boiler tube, as shown in the 
illustration, is extended down in the boiler to a 
point above the level of the side opening to the 
boiler. The water tube should never be extended 
below the level of the side outlet to a boiler, for 
in case water is ever siphoned from the boiler 
through the cold water supply pipe, a condition 
which often happens when water is shut off from 
the building, and a cold water faucet lower down 
subsequently opened, or when water is shut off 
from the street mains for repairs, it would empty 
the water from the boiler to a point below the side 
outlet and water could not then circulate through 
the waterback, which would become overheated. 



28 Hot Water for Domestic Use 

generate steam and cause a rattling, banging noise, 
even if actual damage did not result. If, on the 
other hand, the boiler tube does not extend below 
the level of the side opening and the water becomes 
siphoned from the boiler to the level of the mouth 
of the tube, there will still be sufficient water in the 
boiler to provide for circulation when the return 
pipe from the waterback is connected to the side 
outlet of the boiler. In any event it will insure the 
waterback remaining full of water should siphon- 
age take place. 

If the boiler tube were omitted from a range 
boiler, one of several things might operate to in- 
terfere with the proper operation of the apparatus. 
For instance, if the tube were omitted, cold water 
from the cold water inlet might follow the line of 
least resistance from where it enters the boiler, to 
the outlet for the hot water from the tank. In that 
event, cold water or alternately cold and hot water 
would be drawn from the hot water pipes when a 
faucet was opened. The probability of drawing of 
cold water from a hot water faucet would be in- 
creased in proportion to the nearness the two out- 
lets, the hot and cold water connections, were to 
each other in the top of the boiler. On the other 
hand, the further they were spaced apart, the less 
would be the danger of cold water short-circuiting 
to the hot water pipe, but a condition almost as 
disagreeable would result. The capacity for wa- 



Range Boiler Tube 29 

ter to absorb heat is quite high, and the colder the 
water the more readily it will absorb heat. Conse- 
quently if the boiler tube were omitted, the cold 
water entering at the top where the water in the 
boiler is the hottest, would mingle with the hot wa- 
ter, which it would rob of some of its heat, thus 
interfering with the operation of the hot water 
apparatus. 

Wrought-iron or steel pipe is commonly used for 
a boiler tube. It is needless to say that whichever 
material is used, the pipe should be galvanized both 
inside and outside to prevent as much as possible 
the rusting of the tube, plain black iron boiler 
tubes, after being in service for a while become 
covered with rust which they impart to the water 
within the boilers thus discoloring the water and 
rendering it unfit for most domestic uses. The iron 
rust in water will not only discolor clothes with 
which it comes in contact but will stain vessels and 
plumbing fixtures when there is a sufficient amount 
in the water. 

It is better practice to use a boiler tube of brass, 
copper, Benedict nickel or some equally durable 
and less objectionable material. Boiler tubes made 
of wrought iron or steel have often corroded en- 
tirely through and broken oflf, thus not only doing 
no good but actually being objectionable in the 
boiler, while in many other cases the vent hole 



30 Hot Water for Domestic Use 

usually drilled in a boiler tube has been completely 
choked with a deposit of rust. The cold water 
pipe to a kitchen range boiler is connected to the 
top of the boiler and the cold water conducted down 
through the hot water so that the chill will be taken 
off the cold water before it is finally discharged in- 
to the tank. By employing this means the tem- 
perature of the cold water is slightly raised with- 
out perceptibly affecting the temperature of the 
warm water within the tank. A hole is drilled or 
filed into the side of the boiler tube, near the top; 
the object of this vent hole is to admit air to break 
a siphon and thus prevent the water in the tank 
being lowered below the vent hole. 

The hot water pipe is always connected to the 
top of a kitchen range boiler, because the hottest 
water in the boiler is at the top. 

In many localities the return pipe from the water 
back to the boiler, instead of being connected to 
the boiler at the side opening, is carried to the top 
of the boiler where it is connected either to a spe- 
cial tapping in the boiler provided for that purpose 
or it is connected to a T branch provided in the hot 
water pipe close to the boiler head. By connecting 
a boiler in this manner, hot water can be drawn di- 
rect from the water back at the fixtures, while, 
when the water is not being so drawn it will cir- 
culate through the boiler. Heat can be transmitted 
to the water in a water back much faster than 



Return Pipe to Boiler 31 

it can be absorbed under usual conditions. By 
increasing the velocity of the water, however, the 
quantity of heat transmitted to the water will be 
increased, hence, with the flow pipe connected to 
the top of the boiler, the height of the loop is in- 
creased, the velocity accelerated, and more water 
is heated in a given time than if the flow pipe were 
connected to the side outlet to the boiler. The 
method of connecting the return pipe from a water 
back to the top of a boiler is objected to by some 
authorities. It is claimed by those, and rightly 
too, that should the water be siphoned from the 
boiler to a lower level than the top of the loop, 
from the water back, a condition which would 
surely obtain if the water were siphoned to the 
level of the vent hole in the boiler tube or to the 
bottom of the boiler tube, that there would be a loss 
of circulation. While this is true, there would 
still remain in the boiler such a large volume of 
water that it is doubtful if any harm could re- 
sult before the condition of affairs was observed 
and righted. No damage or accidents, up to the 
present time, at all events, have been traced to this 
method of connecting up boilers. 

Some plumbers combine the two methods. That 
is, they not only connect the flow pipe from the 
water back to the top of the boiler, but they further 
connect a branch from the flow pipe into the side 
outlet of the boiler. 



32 Hot Water for Domestic Use 

Materials for Range Boiler Connections. 

Lead pipe, although extensively used for connect- 
ing a water back to a boiler, is not the most suit- 
able material for this purpose. The lead expands 
when heated and upon cooling does not contract 
to its original length, but sags when run horizon- 
tally and unless supported will form traps, thus 
often causing a rattling in the boiler. Further, the 
manner in which lead pipes are connected together 
or are joined to brass water back and boiler coup- 
lings is an additional objection to its use. Should 
at any time the temperature of the pipe become too 
hot, as, for instance, a fire were started in the range 
without first turning on the water, or should the 
pipe become crusted with lime or magnesia to such 
an extent that water on the inside could not keep 
the pipe cool, the joints on the lead pipe or between 
the lead pipe and the water back couplings are lia- 
ble to pull apart. 

Brass, copper and iron pipe are the materials 
most suited for this purpose. They are strong, 
rigid, will withstand a great degree of heat with- 
out melting and will not sag or stretch out of 
shape. Of course a certain expansion takes place 
when the pipes become heated, but upon cooling 
they return to the normal size and position they 
were in before being heated. To allow for the 
expansion of pipes when heated, the range connec- 
tions between waterback and boiler are or should 



Check and Safety Valves 33 

be made with room for expansion and contraction. 
This is done by seeing that pipes are not tight 
against anything which will interfere with their 
free movement, and by providing swing joints 
where pipes would otherwise be rigid. As was 
pointed out in a former paragraph, the circulation 
of water between the waterback and boiler is 
impeded by friction ; consequently the ends of brass, 
copper or iron pipe, where they are screwed into 
fittings, should be carefully reamed to remove the 
burr formed by cutting the pipe, and 45° bends, 
or large radius 90° bends of recess pattern should 
be used on the flow and return pipe between water- 
back and boiler. Pipes of smaller diameter than 
^-inch should never be used to connect a water- 
back or heater to a boiler or storage tank. For 
connecting an ordinary range boiler to a waterback 
one-inch pipe will be found the most satisfactory, 
while for connecting a water heater to a hot water 
tank, pipes of ij^ inches, 2 inches or even larger 
should be used, the size depending on the size of 
the heater and tank. 

Use of Check and Safety Valves. 

In some localities a check valve is placed in the 
cold water pipe, which supplies the kitchen range 
boiler with water. The object of the check valve is 
to prevent water being siphoned from the boiler in 
case water is shut oflf from the street mains or in 



34 Hot Water for Domestic Use 

the cellar of the building and a cold water faucet 
at a lower level than the boiler opened. Placing 
a check valve in the cold water pipe, however, 
prevents water backing up into the street main 
when it becomes heated and expands. The expan- 
sion of water when heated is no inconsiderable 
amount, as can be seen in Table 3, and, unless pro- 
vision is made to relieve the expansion, the boiler 
or some other part of the system is liable to burst 
from internal pressure. To relieve the excessive 
strain from a range boiler, a safety valve is gen- 
erally provided, when there is a check valve in 
the water supply, and the escape pipe from the 
safety vave is extended to a sink or some other 
point, where in case of a blow off there will be less 
danger of the hot water being scattered over the 
kitchen and possibly scald some one. When boil- 
ers are subjected to siphonic action, the most seri- 
ous result ever experienced is the collapse of the 
boiler from atmospheric pressure. The collapsing 
of a boiler can be prevented by fitting it with a 
vacuum valve placed close to the boiler, on a 
branch to the cold water pipe. The vacuum valve 
is simply a valve which is held closed by the pres- 
sure of water within the mains, but which, when a 
vacuum is formed within the pipes, will open, thus 
admitting air to break the vacuum and prevent 
siphonage of the water from the boiler, with a 
subsequent collapsing of the boiler. 



Expansion Pipe 35 

In some installations both a vacuum valve and a 
safety valve are provided to protect the boiler from 
being collapsed by the atmospheric pressure or from 
being ruptured by internal pressure. Safety valves 
and vacuum valves are used only in systems which 
are supplied with water from the city mains, but 
are unnecessary when water is supplied from a 
tank within the house. 

Expansion Pipe. 

In domestic supplies which are obtained from a 
tank located in the attic of the building, protection 
both from excess pressure due to expansion of 
water and from collapsing due to the formation 
of a partial vacuum in the boiler is provided by 
means of an expansion pipe. An expansion pipe 
consists of a pipe extending from the hot water 
pipe up to and over the house tank, so that any 
steam or water rising in the pipe can flow into the 
tank and not wet the floor or ceiling. While not 
intended for the purpose, yet an expansion pipe 
serves also as a temperature regulator to control 
the temperature of the water within a boiler. 

The pipe being open to the atmosphere prevents 
the pressure rising above a certain amount, and as 
the greatest temperature to which water can be 
raised depends upon the pressure of the water, it 
will be seen that this arrangement which prevents 
a rise in temperature maintains the temperature of 
the water at an almost uniform degree of not much 
over 212° Fahrenheit. 



36 



Hot Water for Domestic Use 



Table III — Comparative Volume and Density 
OF Water at Different Temperatures 

(Calculated by means of Rankine's approximate formula) 
(D. K. CLARK.) 



Tempera- 
ture 
Degrees 


Compara- 
tive 
Volume 
Water at 


Compara- 
tive 
Density 
Water at 


Weight of 

1 cubic 

foot 


Remarkable 
Temperatures 


Fahr. 


32« = 1 


32o = l 


Pounds 




32 


1.00000 


1.00000 


62.418 


Freezing Point. 


35 


0.99993 


1.00007 


62.422 




39.1 
40 


0.99989 
0.99989 


1.00011 
1.00011 


62.425 
62.425 


Point of maximum 
density. 


45 


0.99993 


1.00007 


62.422 




46 
50 


1.00000 
1.00015 


1.00000 
0.99985 


62.418 
62.409 


Same volume and den- 
sity as at the freez- 
ing point. 


52.3 
55 


1.00029 
1.00038 


0.99971 
0.99961 


62.400 
62.394 


Weight taken for ordi- 
nary calculations. 


60 


1.00074 


0.99926 


62.372 




62 


1.00101 


0.99899 


62.355 


Mean temperature. 


65 


1.00119 


0.99881 


62.344 




70 


1.00160 


0.99832 


62.313 




75 


1.00239 


0.99771 


62.275 




80 


1.00299 


0.99702 


62.240 




85 


1.00379 


0.99622 


62.182 




90 


1.00459 


0.99543 


62.133 




95 


1.00554 


0.99449 


62.074 




100 
105 


1.00639 
1.00739 


0.92365 
0.99260 


62.022 
61.960 


Temperature of con- 
denser water. 


110 


1.00889 


0.99119 


61.868 




115 


1.00989 


0.99021 


61.807 




120 


1.01139 


0.98874 


61.715 




125 


1.01239 


0.98808 


61.654 




130 


1.01390 


0.98630 


61.563 




135 


1.01539 


0.98484 


61.472 




140 


1.01690 


0.98339 


61.381 




145 


1.01839 


0.98194 


61.291 




150 


1.01889 


0.98050 


61.201 




155 


1.02164 


0.97882 


61.096 





Volume and Density 



37 



Table III — Continued 



Tempera- 
ture 


Compara- 
tive 
Volume 


Compara- 
tive 
Density 


Weight of 

1 cubic 

foot 


Degrees 
Fahr. 


Water at 
32o = l 


Water at 
32° = 1 


Pounds 


160 


1.02340 


0.97714 


60.991 


165 


1.02589 


0.97477 


60.843 


170 


1.02690 


0.97380 


60.783 


175 


1.02906 


0.97193 


60.665 


180 


1.03100 


0.97006 


60.548 


185 


1.03300 


0.96828 


60.430 


190 


1.03500 


0.96632 


60.314 


195 


1.03700 


0.96440 


60.198 


200 


1.03889 


0.96256 


60.081 


205 


1.0414 


0.9602 


59.93 


210 


1.0434 


0.9584 


59.82 


212 


1.0444 


0.9575 


59.76 


212 


1.0466 


0.9555 


59.64 


230 


1.0529 


0.9499 


59.26 


250 


1.0628 


0.9411 


58.75 


270 


1.0727 


0.9323 


58.18 


290 


1.0838 


0.9227 


57.59 


298 


1.0899 


0.9175 


57.27 


338 


1.1118 


0.8994 


56.14 


366 


1.1301 


0.8850 


55.29 


390 


1.1444 


0.8738 


54.54 



Remarkable 
Temperatures 



Boiling point by formula 
Boiling point by direct 
measurement. 



Temperature of steam 
of 50 lbs. effective 
pressure per square 
inch. 

Temperature of steam 
of 100 lbs. pressure 
per square inch. 

Temperature of steam 
of 150 lbs. pressure 
per square inch. 

Temperature of steam 
of 205 lbs. effective 
pressure per square 
inch. 



38 Hot Water for Domestic Use 

Check Valves for Cold Water Supply. 

There are two types of check valves used around 
hot water boilers to prevent a back-flow to the 



tntef 




Fig:. 6. 



Fiff. 7. 



water mains; they are known respectively as lift 
check valves 2in^ swing check valves, A lift check 
valve is shown in Fig. 5. When passing through 



Check and Safety Valves 39 

this type of valve, water flows through the inlet, 
raises the valve disk from its seat and flows in 
the direction of the arrow toward the outlet. In 
case the pressure is greater on the outlet side of 
the valve the disk is seated the more firmly by the 
pressure and no water can escape through unless 
the valve leaks. In the swing check valve, shown 
in Fig. 6, there is less resistance offered to the 
flow of water than in the lift check valve. This 
makes the swing check valve better suited for use 
in places where the water pressure is very low, or 
in circulating circuits where the flow is sluggish. 
When water flows into the outlet end of this valve, 
which is at the left side, the pressure swings the 
gate a on the hinge h and permits the water to 
flow through, but closes immediately should a back 
pressure set in toward the opposite direction. 

A safety valve, such as may be used over a hot 
water boiler in connection with a check valve is 
shown in section in Fig. 7. In this device, the 
disk is held on its seat by means of a spring which 
can be set to open at any desired pressure. Usually 
the spring is adjusted to open at a pressure of from 
10 to 15 pounds above the normal pressure of the 
water supply. A lever at the right-hand side of 
this safety valve is provided so the valve can be 
tested from time to time to see that it is not stuck 
to the seat. By attaching a chain to the lever a 
person standing on the floor of the kitchen can try 



40 Hot Water for Domestic Use 

the valve at pleasure. Safety valves which are 
kept closed by means of a weight or ball of iron 
are seldom used for this purpose, particularly when 
the hot water boiler is located in the kitchen. 

Boiling Points of Water. 

By the boiling point of water is meant the tem- 
perature at which ebullition takes place. The boil- 
ing point of water, which is also the temperature 
at which steam forms, depends upon the elevation 
with regard to sea level when the vessel is un- 
covered, or to the pressure when the vessel is en- 
closed. In other words, it may be said that the 
temperature at which water boils varies with the 
pressure. Thus, in a vacuum of 13.69 pounds be- 
low atmospheric pressure, water boils at a tempera- 
ture of 102° Fahrenheit, which is but slightly above 
blood heat. At atmospheric pressure, at sea level, 
which is generally taken to be 14.7 pounds per 
square inch, water boils at a temperature of 212 
degrees Fahrenheit, which is likewise the tempera- 
ture at which steam forms in an open vessel. At 
15.31 pounds above atmospheric pressure, water 
boils at a temperature of 250° Fahrenheit. In 
short it may be said that the temperature of boiling 
water and the temperature of steam in contact with 
the water are always equal, and the pressure of 
boiling water and the pressure of steam in contact 
are always equal. Further, there is a certain defi- 



Boiling Points of Water 41 

nite relation between the pressure and temperature 
of the water and steam in contact. The pressure 
cannot be increased without increasing the boiHng 

Table IV. 



1^ 

ill 

^2S 


%i m 


© a)«wM^ 


9i QQ 


^ OQ 


a)a>vi+JV4 


o o 

¥ 

■M 


Ratio of Tolum 
of steam to volum 
of equal weight o 
distilled water a 
temper ature o 
maximum density 


a a 

2-2 


^0, 

a Si 

ill 


Ratio of volum 
of steam to volum 
of equal weight o 
distilled water a 
tempera ture o 
maximum density 


1 


2 


3 


1 


2 


3 


1 


102.018 


20623 


46 


275.704 


563.0 


2 


126.302 


10730 


48 


278.348 


540.9 


3 


141.654 


7325 


50 


280.904 


520.5 


4 


153.122 


5588 


52 


283.381 


501.7 


5 


162.370 


4530 


54 


285.781 


484.2 


6 


170.173 


3816 


56 


288.111 


467.9 


7 


176.945 


3302 


58 


290.374 


452.7 


8 


182.952 


2912 


60 


292.575 


438.5 


9 


188.357 


2607 


62 


294.717 


425.2 


10 


193.284 


2361 


64 


296.805 


412.6 


11 


197.814 


2159 


66 


298.842 


400.8 


12 


202.012 


1990 


68 


300.831 


389.8 


13 


205.929 


1845 


70 


302.774 


379.3 


14 


205.604 


1721 


72 


304.669 


369.4 


14 69 


212.000 


1646 


74 


306.526 


360.0 


15 


213.067 


1614 


76 


308.344 


351.1 


16 


216.347 


1519 


78 


310.123 


342.6 


17 


219.452 


1434 


80 


311.866 


334.5 


18 


222.424 


1359 


82 


313.576 


326.8 


19 


225.255 


1292 


84 


315.250 


319.5 


20 


227.964 


1231 


86 


316.893 


312.5 


22 


233.069 


1126 


88 


318.510 


305.8 


24 


237.803 


1038 


90 


320.094 


299.4 


26 


242.225 


962.3 


92 


321.653 


293.2 


28 


246.376 


897.6 


94 


323.183 


287.3 


30 


250.293 


841.3 


96 


324.688 


281.7 


32 


254.002 


791.8 


98 


326.169 


276.3 


34 


257.523 


748.0 


100 


327.625 


271.1 


36 


260.883 


708.8 


105 


331.169 


258.9 


38 


264.093 


673.7 


110 


334.582 


247.8 


40 


267.168 


642.0 


115 


337.874 


237.6 


42 


270.122 


613.3 


120 


341.058 


228.3 


44 


272.965 


587.0 









point of the water and the temperature at which 
steam forms; and, conversely, the temperature of 



42 Hot Water for Domestic Use 

the water cannot be increased without increasing 
the pressure of the water and of the steam with 
which it is in contact. This is important to know 
for when the pressure carried in the city water 
mains is known, the temperature at which water 
will boil in the water back and hot water tank 
can easily be determined. For instance, if the 
pressure of water in the street mains be lOO pounds 
per square inch, a common pressure for city water 
mains, the temperature corresponding to that 
pressure, at which the water will boil, will be about 
337° Fahrenheit. The relative pressures and tem- 
peratures of boiling water and steam in contact, 
from about 15 pounds vacuum to 105 pounds 
gauge pressure, can be found in Table IV. In 
this table the pressures are stated as absolute 
pressures so that 14.69 pounds must be deducted 
from each reading to determine the gauge pressure 
at which water boils. In addition to the boiling 
points and corresponding pressures, the table gives 
the ratio of volume of steam, to a volume of equal 
weight of pure water, when converted into steam 
and subjected to the pressure indicated. For in- 
stance, one pound of water when converted into 
steam, and subjected to an absolute pressure of 46 
pounds per square inch, would expand in volume 
to 563 times the bulk of the original pound of 
water. 



Pressure of Water 



43 



Pressure of Water. 

In dealing with water pressures, it is well to 
know just what is meant by the various terms. 
There are two kinds of pressures used in hydrau- 
lics, gauge pressure and absolute pressure. It is 
well known that the atmosphere exerts, or is sub- 
jected to a pressure of approximately 14.7 pounds 
per square inch, and when pressure is calculated 
from the zero pressure of atmosphere, the pressure 
is absolute; and the ordinary atmospheric pressure, 
everything is subjected to, is rated at 14.7 pounds 
per square inch. Ordinarily, however, the pressure 

of the atmos- 
phere is ignored, 
and pressure 
readings are 
taken from the 
14.7 point, 
which is consid- 
ered zero. Thus 
it is that the 
gauge pressure 
takes no account 
of the pressure 
of the atmos- 
phere, and 
gauges indicate only the additional pressure above 
atmospheric. To find the absolute pressure of 




Fig. 



44 Hot Water for Domestic Use 

water, therefore, when gauge pressure is given, 
add 14.7 pounds to the readings of the gauge. When 
absolute pressures are given they can be converted 
into gauge pressures by substracting 14.7 pounds 
from the absolute pressure. 

The pressure of water in closed systems is gen- 
erally indicated by means of a pressure gauge. 
The construction and principle of operation of a 
pressure gauge can be seen in Fig. 8. The dial 
face has been removed in this illustration to show 
the interior construction and operation of the ap- 
paratus. The construction of the gauge is as fol- 
lows: A bent tube a of elliptical cross-section, 
made of a suitable metal of the required elasticity, 
has its bottom end firmly attached to the gauge 
case and its upper end free to move. To the upper 
end is attached a lever, b, which is connected to a 
pointer in front of the dial face, in such a manner 
that any movement of the tube will be indicated 
by the pointer on the graduated index on the face 
of the gauge. The gauge operates on the principle 
that if a bent tube of elliptical cross-section is sub- 
jected to internal pressure, the force exerted will 
tend to straighten the tube. This is due to the fact 
that a force exerted within a tube of elliptical cross- 
section tends to make it take a circular form ; to do 
so the inner arc of the bent tube must lengthen and 
the outer arc shorten, and the combined effort will 
straighten the tube in direct proportion to the 



Transmission of Heat 45 

pressure exerted. The straightening of the tube 
imparts a movement to the register hand which in 
turn indicates on the face of the gauge the inten- 
sity of the pressure. 

How TO Determine Pressure of Water. 

Without the use of a gauge the pressure of water 
can be determined, when the height of the column 
is known. One foot depth of water, one inch 
square, weighs approximately .434 of a pound, and 
by multiplying the depth of water in feet by the 
constant .434 will give the pressure per square inch 
on the base of the column of water. Pressure is 
but another name for weight when applied to water 
and instead of calculating the pressure or weight 
of water, it may be determined for heads from i 
foot in depth to 240 feet in depth, by referring to 
Table V. 

Transmission of Heat to Water. 

The amount of heat that can be transmitted to 
water, depends on the volume of the fluid and its 
temperature. There is, however, a certain quantity 
of heat which can be transmitted to a unit volume 
of water and the amount of heat which can be 
transmitted to the unit volume varies with and is 
constant for the different temperatures. Further- 
more, the quantity of heat, or the number of B. T. 
U. required to raise the temperature of a unit 
volume of water to the boiling point is constant 
and applies to every case. For instance, it requires 



46 Hot Water for Domestic Use 

Table V. 
Pressure of Water at Various Heads. 



u 


2»« 




d^3 






1% 




W5 


P? 




6 ^ 




6 S 




•2 s 




•2 S 




«a c 




si -t 




C ri 




M >-t 




^ ^ 




|3 




r 








p3 




to (0 

3 




1 


0.43 


49 


21.22 


97 


42.01 


145 


62.81 


193 


83.60 


2 


0.86 


50 


21.65 


98 


42.45 


146 


63.24 


194 


84.03 


3 


1.30 


51 


22.09 


99 


42.88 


147 


63.67 


195 


84.47 


4 


1.73 


52 


22.52 


100 


43.31 


148 


64.10 


196 


84.90 


5 


2.16 


53 


22.95 


101 


43.75 


149 


64.54 


197 


85.33 


6 


2.59 


54 


23.39 


102 


44.18 


150 


64.97 


198 


85.76 


7 


3.03 


55 


23.82 


103 


44.61 


151 


65.40 


199 


86.20 


8 


3.46 


56 


24.26 


104 


45.05 


152 


65.84 


200 


86.63 


9 


3.89 


57 


24.69 


105 


45.48 


153 


66.27 


201 


87.07 


10 


4.33 


58 


25.12 


106 


45.91 


154 


66.70 


202 


87.50 


11 


4.76 


59 


25.55 


107 


46.34 


155 


67.14 


203 


87.93 


12 


5.20 


60 


25.99 


108 


46.78 


156 


67.57 


204 


88.36 


13 


5.63 


61 


26.42 


109 


47.21 


157 


68.00 


205 


88.80 


14 


6.06 


62 


26.89 


110 


47.64 


158 


68.43 


206 


89.23 


15 


6.49 


63 


27.29 


111 


48.08 


159 


68.87 


207 


89.66 


16 


6.93 


64 


27.72 


112 


48.51 


160 


69.31 


208 


90.10 


17 


7.36 


65 


28.15 


113 


48.94 


161 


69.74 


209 


90.53 


18 


7.79 


66 


28.58 


114 


49.. 38 


162 


70.17 


210 


90.96 


19 


8.22 


67 


29.02 


115 


49.81 


163 


70.61 


211 


91.39 


20 


8.66 


68 


29.45 


116 


50.24 


164 


71.04 


212 


91.83 


21 


9.09 


69 


29.88 


117 


50.68 


165 


71.47 


213 


92.26 


22 


9.53 


70 


30.32 


118 


51.11 


166 


71.91 


214 


92.69 


23 


9.96 


71 


.30.75 


119 


51.54 


167 


72.34 


215 


93.13 


24 


10.39 


72 


31.18 


120 


51.98 


168 


72.77 


216 


93.56 


25 


10.82 


73 


31.62 


121 


52.41 


169 


73.20 


217 


93.99 


26 


11.26 


74 


.32.05 


122 


52.84 


170 


73.64 


218 


94.43 


27 


11.69 


75 


,32.48 


123 


53.28 


171 


74.07 


219 


94.86 


28 


12.12 


76 


,32.92 


124 


53.71 


172 


74.50 


220 


95.30 


29 


12.55 


77 


33.35 


125 


54.15 


173 


74.94 


221 


95.73 


30 


12.99 


78 


33.78 


126 


54.58 


174 


75.37 


222 


96.16 


31 


13.42 


79 


34.21 


127 


55.01 


175 


75.80 


223 


96.60 


32 


13.86 


80 


34.65 


128 


55.44 


176 


76.23 


224 


97.03 


33 


14.29 


81 


35.08 


129 


55.88 


177 


76.67 


225 


97.46 


34 


14.72 


82 


35.52 


130 


56.31 


178 


77.10 


226 


97.90 


35 


15.16 


S3 


35.95 


131 


56.74 


179 


77.53 


227 


98.33 


36 


15.59 


84 


36.39 


132 


57.18 


180 


77.97 


228 


98.76 


37 


16.02 


85 


.36.82 


133 


57.61 


181 


78.40 


229 


99.20 


38 


16.45 


86 


37.25 


134 


58.04 


182 


78.84 


230 


99.63 


39 


16.89 


87 


37.68 


1.35 


58.48 


183 


79.27 


231 


100.06 


40 


17.32 


8S 


.38.12 


1.36 


58.91 


184 


79.70 


232 


100.49 


41 


17.75 


89 


38.55 


137 


59.34 


185 


80.14 


233 


100.93 


42 


18.19 


90 


38.98 


138 


59.77 


186 


80.57 


234 


101.36 


43 


18.62 


91 


.39.42 


139 


60.21 


187 


81.00 


235 


101.79 


44 


19.05 


92 


39.85 


140 


60.64 


188 


81.43 


236 


102.23 


45 


19.49 


93 


40.28 


141 


61.07 


189 


81.87 


237 


102.66 


46 


19.92 


94 


40.72 


142 


61.51 


190 


82.30 


238 


103.09 


47 


20.35 


95 


41.15 


143 


61.94 


191 


82.73 


239 


103.53 


48 


20.79 


96 


41.58 


144 


62.37 


192 


83.17 


240 


103.96 



Pressure of Water at Various Heads. 47 

212 B. T. U. to raise the temperature of one pound 
of water from zero to 212° Fahrenheit, and it will 
take 106 B. T. U. to raise to the boiling point 
Table VI. 

B. T. U. AT DIFFERENT TEMPERATURES. 

Number of 
B. T. U. required to 
raise the Tempera- 
Number of ture of the Water 
Temperature, B. T. U., reckon- to Boiling Point, 
Degrees Fahr. ing from 0*. 212" Fahr. 

.35 35.000 177.900 

40 40.001 172.899 

45 45.002 167.898 

50 50.003 162.897 

55 55.006 157.894 

60 60.009 152.891 

65 65.014 147.886 

70 70.020 142.880 

75 75.027 137.873 

80 80.036 132.864 

85 85.045 127.855 

90 90.055 122.845 

95 95.067 117.833 

100 100.080 112.820 

105 105.095 107.815 

110 110.110 102.790 

115 115.129 97.771 

120 120.149 92.751 

125 125.169 87.731 

130 130.192 82.708 

135 135.217 77.683 

140 140.245 72.655 

145 145.275 67.625 

150 150.305 62.585 

155 155.339 57.561 

160 160.374 52.526 

165 165.413 47.487 

170 170.452 42.447 

175 175.497 37.403 

180 180.542 32.358 

185 185.591 27.309 

190 190.643 22.257 

195 195.697 17.203 

200 200.753 12.147 

205 205.813 7.087 

210 210.874 2.016 



48 Boiling Point of Water 

water which has a temperature of io6° Fahrenheit. 
The number of B. T. U. contained in one pound 
of water at different temperatures, also the number 
of B. T. U. required to raise one pound of water, 
from different temperatures to the boiling point at 
atmospheric pressure, may be found in the table on 
the preceding page. 



Hot Water for Domestic Use 49 



HEATING WATER BY 
KITCHEN RANGES 

The water stored in range boilers, for use in the 
home, is generally heated in a water back, located 
in the firebox of the kitchen range. In this sense 
the term waterback is used to indicate the appa- 
ratus used for heating water, regardless of its loca- 
tion in the firebox. Some ranges have the heating 
coil casting located at the front of the firebox, in 
which case, strictly speaking, they are water fronts. 
In some the casting is at the end of the firebox, 
in which case they are water ends. Other ranges 
have the casting located at the back of the firebox, 
in which case they are water backs. For con- 
venience in referring to them, however, they will be 
referred to indiscriminately as waterbacks, as the 
principles of installation and the connections to the 
differently located castings are all the same. 

A waterback is simply a hollow casting with two 
tapped openings for connecting pipes to. The cast- 
ing, being located in the firebox, absorbs heat from 
the flames, and the hot gases coming in contact with 
it, which in turn is transmitted to the water within 
the casting. As this water becomes heated it like- 
wise becomes lighter and is displaced by colder 
water, thus setting up a circulation between the 
waterback and the boiler. Sometimes the waterback 



50 



Hot Water for Domestic Use 



has a partition cast horizontally part way across it, 
so that the water will have to flow the full length 
of the casting. A waterback, such as is used for 
kitchen ranges, is shown in Fig. 9. This waterback 




Fig. 9. 

is made with a partition, a, cast part way across 
it, so that the circulating water will have to flow 
in the direction of the arrow. If it were not for 
this partition some water could short circuit from 
the inlet to the outlet, without becoming thoroughly 
heated. The opening for the flow pipe, bj should 
be tapped close to the top wall of the waterback, 
so that the very hottest water in the casting can 
flow out, and not be trapped to become converted 
into steam. 

Waterbacks are made much thicker than would 
seem necessary to withstand the pressure of water 
to which they are subjected, but it must be remem- 
bered that when manufactured nobody knows where 



Strength of Water Backs 51 

or under what conditions they will be used, conse- 
quently they are made to withstand the worst pos- 
sible use. The casting might be used in connection 
with a low pressure job, where it will never be sub- 
jected to a greater internal pressure than 20 pounds 
per square inch, or it might be used in a locality 
where the pressure on the street mains is over 100 
pounds per square inch, and when, owing to depos- 
its of lime, the waterback becomes partly or wholly 
obstructed and becomes then subjected to much 
severer use. Furthermore, the casting is subjected 
to severe stresses at times, owing to the cold water 
within the waterback and the intense fire outside. 
To provide for all these various stresses to which 
waterbacks are exposed, they are designed to with- 
stand an ultimate pressure of 700 pounds per square 
inch. Even this strength is not sufficient in extreme 
cases of neglect and we often hear or read of water- 
backs bursting with disastrous results. The damage 
done by a bursting waterback can easily be realized, 
when it is considered that the bursting pressure 
must become 700 pounds per square inch. 

The most common cause of waterbacks bursting 
is freezing of the water in the waterback, or con- 
nections. Consequently, where ranges are exposed 
in cold places, during winter weather, extra precau- 
tions should be observed to see that the water pipes 
do not freeze, and if the fire in the range goes out 
during the night, before firing up in the morning. 



52 Hot Water for Domestic Use 

it is well to make sure that the waterback, flow 
and return pipes are free from ice. Plumbers in- 
stalling hot water apparatus in cold places should 
caution their customers with regard to the danger 
from frost. 

It would seem needless to remark that valves, 
cocks or checks of any kind should not be placed 
either in the flow or return pipe to a boiler; yet, 
so many installations have valves in them, that the 
objection to them cannot be too forcibly pointed 
out. If for any reason a stop cock or valve in one 
of these installations should become closed through 
ignorance, carelessness or neglect, steam would form 
in the waterbacks, and if the pressure became suf- 
ficient, burst the casting. 

The size of a waterback is the heating surface it 
contains in square inches, measuring only that side, 
or side and edge which are exposed to the fire. 
The average size of waterback contains about no 
square inches and will heat the water in a water 
tank containing 40 gallons of water, for an ordi- 
nary family. The waterbacks in ranges for hotels, 
restaurants, clubs, and like institutions are made 
larger than the waterbacks to family ranges and 
will heat more water, the capacities being deter- 
mined in each case by the range manufacturer. 
Incrustation of Waterbacks. 

The rock formation of the surface of the earth 
seems to be largely limestone, and water passing 



Incrustation in Water Backs. 53 

through it becomes impregnated with this lime to 
such an extent that it not only refuses to work in 
harmony with the compound known as soap, but it 
so incrusts waterbacks, coils in heaters and furnaces, 
flues in steam boilers and connecting pipes, that in 
a comparatively short time they clog up or become 
ineffective. 

To overcome this characteristic of limestone water 
has been a long and ardent study and an endless 
experiment. The observing mechanic, as well as 
the careful housewife, has long since discovered 
that one of the greatest nuisances and most expen- 
sive items is this adhesion of lime from hard water. 
It is stated that ninety per cent of the inland cities 
are supplied with hard water for domestic use. 

Water impregnated with hardenable carbonates 
and sulphates of lime, magnesia and other incrust- 
ing minerals, cause not only loss of full value of 
heat and steam, but also frequent repair bills. If 
scale can be prevented, there is a large saving of 
fuel. It is stated that an eighth of an inch of scale 
adds nearly one-fourth to the fuel bill. 

When a waterback becomes so incrusted with 
lime, magnesia and other incrusting minerals, that 
there is danger of a complete stoppage, or when 
the incrustation becomes so thick on the walls of 
the casting that sufficient heat is not transmitted to 
the water, the waterback must be taken from the 



54 Hot Water for Domestic Use 

fire-box and cleaned or provided with an apparatus 
that will clean it. 

To do so, the water is first shut off, the water 
emptied from the boiler and the pipes then discon- 
nected, after which the casting can be lifted out of 
the range fire-box. The water is emptied from the 
boiler by opening the draw-off cock at the bottom 
of the boiler and turning on a hot water faucet at 
some fixture in the building, so that air will be ad- 
mitted to the boiler to replace the water withdrawn. 
If air is not admitted to the boiler no water will 
run out, but, on the contrary, it will remain air- 
bound within the tank, just the same as if a bottle 
of water be inverted. Sometimes the hot water 
pipes in a building are trapped, and air cannot flow 
into the boiler when a hot water faucet is opened. 
When such is the case the hot water supply coupling 
on top of the boiler should be uncoupled to let in air. 

Sometimes the incrustation inside the waterback 
is flaky, and can easily be scaled off or detached by 
pounding the casting on all sides with a hammer and 
jarring the lime out of the pipe openings by drop- 
ping it, the open end down, on a plank or block of 
wood provided for that purpose. When the scale is 
not so easily removed, particles can be detached 
by means of a long slender chisel, worked through 
the openings to break up the scale. 



Cleaning Water Backs 55 

Sometimes the incrusting material is of such 
quaUty, or has been baked so hard to the sides of 
the waterback that it cannot be reached by ordinary 
means ; then it becomes necessary to provide the 
waterback with an apparatus that will soften the 
water ere it enters the waterback, and the old scale 
will then gradually come off as the water disin- 
tegrates the lime. 

Preventing the Incrustation of Waterbacrs. 

By making special provision against the deposits 
of lime, magnesia and other incrusting minerals in 
waterbacks and coils, the incrustation can be 
entirely checked where water that is very hard must 
be heated. To prevent incrustation, the hard water 
must be neutralized or partly softened ere it enters 
the waterback or boiler. The water may be treated 
by a special apparatus such as shown in Figure lo. 
With this apparatus, which is automatic in opera- 
tion, the feeder or chamber is supplied with a brick, 
a water softening composition, the supply being auto- 
matically controlled by two valves on the apparatus, 
which can be regulated to such a point that all the 
water is neutralized before it enters the heating ap- 
paratus. 

The water softening composition converts the sul- 
phates and carbonates in the water into phosphates, 
which cannot harden, making the formation of scale 
an impossibility. This composition is harmless when 



56 



Hot Water for Domestic Use 



used in the water for culinary, drinking or toilet 
purposes, or, in other words, the water can be used 
for the same purposes as before the apparatus was 
installed. 

For residences and small institutions, where a 30 
or 40 gallon range boiler is installed, the above 
apparatus should be connected in the cold water 
supply pipe in basement leading to range boiler as 




Fig. 10. 

shown in Fig. 11. By connecting the apparatus in 
the cold water pipe all the cold water will be neu- 
tralized before entering the boiler and the water 
will circulate through the apparatus only when hot 
water is being drawn from the range boiler; hence 
it will be impossible to have any lime, magnesia or 
other incrusting minerals accumulate in the pipe 
connection or boiler. 



Preventing Incrustation in Range Boilers. 57 



For large institutions such as hotels, restaurants, 
hospitals, barber shops, city and county institutions. 



k 






■f- 



yita 



Fig. 11 



where large quantities of water are consumed daily, 
the apparatus should be connected in the feed or 
cold water pipe to heater, as shown in Fig. 11a. 



58 Cleaning Water Backs 




Fig. lla. 



Cleaning Water Backs 59 

It will be seen that the range boiler and range 
have the usual pipe connections, and that the appara- 
tus is connected in the feed or cold water pipe. After 
the apparatus has been installed and the cold water 
turned into the system, open the hot water faucets 
to allow the grease and dope to leave the system 
(which usually enters the system when cutting the 
pipe and making new connections). 

When the water is clear and free from grease and 
dope, turn the two valves off on the apparatus, open 
the drain cock at bottom of apparatus, then unscrew 
cover from the top of apparatus, drop a brick of 
water-softening composition into the basket in 
feeder, screw cover down tight, close drain cock, 
then open the two valves with one revolution, when 
all will be ready for action as soon as fire is started 
in the range. 

It is said that one brick water-softening compo- 
sition will neutralize from 3,000 to 5,000 gallons of 
hard water, depending upon the acidity of the water. 
It can be ascertained by the hardness of the water 
if the brick is consumed. It is important to have 
a fixed time for charging the apparatus. The sedi- 
ment cock at the bottom of the range boiler should 
be opened at least once a week to blow out the sedi- 
m.ent and keep the water from getting roily. 



60 Hot Water for Domestic Use 



Deposits of Mud in Waterbacks and Boilers. 

In many localities, particularly on the banks of 
turbid streams, or rivers, from which the munici- 
pality receives its supply of water, so much mud 
and sediment is carried in suspension that the water 
presents a very muddy appearance. When kept 
constantly stirred up by the agitation incident to 
flowing through pipes, the mud remains suspended 
in the water, but if allowed to remain quiescent 
for a few hours, as for instance, in hot water boilers, 
and closet tanks over night, a large percentage of 
the mud will settle to the bottom, where if not 
again stirred up, it will remain until removed by 
some means. By using a properly constructed mud 
collector or draw-off in connection with a boiler, 
the sediment can be separated from the water and 
drawn off at intervals without stirring up the mud, 
consequently, the hot water supply, when such pro- 
vision is made, will be clearer than it otherwise 
would, and the waterback will be protected from 
a deposit of mud, which, when baked on becomes 
so hard that it is difficult to remove. Mud, it might 
be stated, cannot be treated like hardness of water, 
to prevent incrustation, but the only way is to re- 
move as much as possible of the mud content of 
the water. A simple means of accomplishing this 



Mud Deposits 



61 



is to use a device similar to that shown in 
Fig. 12. To use this device, the bottom connec- 
tion to the boiler must be larger than the stand- 
ard size. Into this en- 
larged opening the mud 
connection is screwed. 
The connection consists 
of an enlarged pocket or 
fitting, with the return 
pipe connection to the 
waterback passing up 
through the center of it 
to a distance of several 
inches above the level of 
the bottom of the boiler. 
Around this stand pipe 
is an annular space 
through which mud, fol- 
lowing the natural slope 
of the bottom of the 
boiler' can settle down 
into the mud pocket. It 
will be noticed that when 
such a fitting is used, 
there is little or no dan- 
ger of the mud becoming 
stirred up by the circulation of water between the 
waterback and boiler, unless through carelessness in 
not drawing off the mud occasionally through the 




Fig. 12. 



62 Hot Water for Domestic Use 

blow-off connection, it is allowed to accumulate until 
it reaches a point above the top of the return pipe 
to the waterback. 

Pipe Coils for Heating Water. 

Some cooking stoves and ranges are not provided 
with waterbacks for heating water, and sometimes 
it is desirable to heat water in an ordinary heating 
stove, furnace, or other type of heater. Under 
such conditions heating coils, made of pipe, are 
used to supply the deficiency of waterback or water 
jacket. Usually pipe coils are made of plain, 
wrought-iron, or steel pipe, put together with ordi- 
nary steam fittings generally of the return bend 
pattern. In other cases the coil is made of copper 
or brass tubing, bent to fit its final resting place in 
the firebox. Whatever the material used, the ends 
are threaded and made long enough to project 
through the side of the cooking range or heaters 
so that they can be connected to the flow and re- 
turn outlets of the boiler. Pipe coils are usually 
made and installed by the plumber or steam fitter, 
and great care must be exercised in doing this 
work, if satisfactory results are to be obtained. 
The first precautions must be observed in locating 
and drilling the holes through the side of the fire- 
box, to get them in their right places, and not to 
break the thin casting, which is easily cracked. 



Heating Water by Pipe Coils 63 

Good judgment and extreme care must also be ex- 
ercised in placing a coil within a firebox, to see 
that it does not in any way interfere with or de- 
range the other functions of the range or heater. 
There is less danger of this in a heater than there 
is in a cooking stove or range. The principal ob- 
jection to placing a heating coil in a range is the 
fact that its effect on the draft of the stove or 
heating capacity of the oven can never be foretold. 
As a consequence, ovens are often spoiled for baking 
and roasting by placing a waterheating coil in the 
range, if not designed to accommodate one, or by 
improperly installing a coil in a range, that if prop- 
erly installed would work satisfactorily. 



64 



Hot Water for Domestic Use 



Special Water Heaters. 

Where large quantities of water must be heated, 

such as in apartment houses, clubs, hotels, hospitals, 

bathing establishments, swimming pools, baptistries 

and for other purposes which might arise in practice, 

special heaters are 
^^^ , , yrrr^ rcquircd, unless the 
water is heated by 
steam. For this pur- 
pose, what might ,be 
called a water- jacket- 
ed stove is used. One 
type of such water 
heater is shown in 
Fig. 13. It consists 
of a firebox encased 
with a double casing 
between the walls of 
which water can cir- 
culate and absorb 
heat from the hot 
coals, and gases 
against the inner cas- 
ing. Water enters 
this water jacket as 
the space formed by the two walls is called, through 
an opening near the bottom, and after becoming 
heated, passes out through the hot water opening 
near the top of the casing. The water heating part 




Fig. 13. 



Special Water Heaters 65 

of the apparatus is mounted on an ash pit and over 
a coal grate, so that fuel can readily be burned 
within. 

Water heaters are made of cast iron and of steel, 
and in capacities ranging from 50 to 600 gallons 
per hour. Larger sectional heaters are made with 
capacities up to several thousand gallons of water 
per hour. Water heaters are also made for hand- 
feed and for magazine feed. The one shown in the 
illustration is a magazine feed heater. The magazine 
feeding apparatus consists simply of a tube or coal 
chute in the center of the heater which will hold 
several hours supply of coal, which is automatically 
fed to the fire as required. A magazine fed heater 
can be converted into a hand fed heater by re- 
moving the magazine, but conversely, a hand fed 
heater cannot be converted into a magazine fed 
heater, because no provision is made for a magazine 
in the hand fed types. 

Connections to Water Heaters. 

The connections to water heaters vary in size 
according to the capacity of the heater. Heaters 
having capacities of 50 gallons per hour usually 
have 1 54 -inch connections. Those having 100 gal- 
lons capacity have ij4-inch connections, and heaters 
of 150 gallons capacity have 2-inch connections. 

The quantity of water that can be heated by a 
water heater depends on the area of the grate sur- 
face. It is commonly accepted in practice that one 



66 Hot Water for Domestic Use 

square foot of grate surface will heat from 35 
to 40 U. S. gallons of water per hour from or- 
dinary temperature to about 200° Fahrenheit. So 
this will be found a safe allowance for ordinary 
purposes when the amount of hot water required 
is known. It might be well to add, in passing, 
that a water heater to give good service, should 
have a good, well proportioned flue. There is an 
intimate relation between the size or area of grate 
in a water heater and the area of smoke flue to 
which the heater is connected, and unless this rela- 
tion is maintained and the two proportioned to each 
other, although the heater is otherwise rightly pro- 
portioned, it will not give the degree of satisfaction 
that might be expected. If the smoke flue is small, 
crooked and rough inside, the draft will be checked 
and less air will be brought in contact with the 
fuel than would be the case if the flue were large, 
straight and smooth inside. In operating the heater 
there will likewise be a marked difference. With 
a good smoke flue the fire will respond readily to 
the manipulation of the drafts, springing up and 
burning brightly as soon as they are opened, while 
with a small flue, the fire at its best will be sluggish. 
In practice it is customary to allow for smoke flue 
one-eighth of the sectional area of the grate sur- 
face. That would be equal to 18 square inches 
area in the smoke flue for each square foot of grate 
surface. 



Smoke Flues 



67 



Having provided a good smoke flue for the 
water heater, no other smoke pipes should be per- 
mitted to connect to it, nor should other openings 
to the flue be allowed. Two fires on one smoke 
flue will spoil the draft so that neither fire will be 
satisfactory. 

Garbage Burning Water Heaters. 
In many institutions like asylums, poor farms, 

hospitals and sanitari- 
ums there is an accu- 
mulation of combust- 
ible mterials which 
must be disposed of, 
as well as a greater or 
less amount of gar- 
bage, in the shape of 
refuse of vegetables 
prepared for meals, 
which would become a 
nuisance if not cared 
for in a sanitary man- 
ner. In such institu- 
tions there generally 
is plenty of help to 
look after fires, and 
garbage burning 
„. , , water heaters may be 

Fig. 14. -^ 

used for heating 
water, using combustible materials like paper and 




68 Hot Water for Domestic Use 

scraps of wood for fuel, and consuming the gar- 
bage from the institution at the same time. In case 
it is desired to dispose of papers and other com- 
bustible materials otherwise, coal may be used for 
fuel in the garbage burning heater, the same as in an 
ordinary water heater. A garbage burning heater is 
shown in Fig. 14. It differs from an ordinary water 
heater principally in having a shelf made of pipe 
coils, through which water circulates and on which 
garbage may be dumped to dry out and be burned. 
Heating Water With Gas. 
Gas has come into such general use, within recent 
years, for cooking of meals and other household 
purposes, that it is not surprising to find it invading 
the field of coal, in the heating of water for domes- 
tic use. The value of gas as a fuel lies in the fact 
that as soon as it is lighted, the maximum degree 
of heat is immediately developed, and this heat can 
be applied at any convenient point in a heating ap- 
paratus. On account of the heat immediately reach- 
ing its maximum degree, as soon as the gas is 
lighted, and the fact that a certain percentage of the 
heat contained in gas is not required to produce a 
draft to promote combustion, as in the case of coal, 
ordinary illuminating gas can easily compare with 
coal in economy and can be used in some installa- 
tions where coal would be too expensive. Ordinary 
illuminating gas contains between 650 and 700 avail- 
able B. T. U/s per cubic foot, and this heat is suf- 



Gas as Fuel 69 

ficient to raise the temperature of one gallon of 
water from ordinary temperature, which is 62 de- 
grees Fahrenheit, to between no and 120 degrees 
Fahrenheit; as 120 degrees Fahrenheit is as warm 
as water is required for bathing, dish-washing, laun- 
dry work and other household uses, it may be 
roughly estimated that one cubic foot of ordinary 
illuminating gas will heat one gallon of water to a 
suitable temperature for domestic uses. The con- 
venience of gas, the lack of dust and ashes are addi- 
tional considerations which recommend gas for 
heating water ; and with the various appliances now 
on the market, a suitable heater can be obtained for 
use under most any known condition of service. 
Roughly, the gas burning apparatus used for heat- 
ing water may be divided into three different classes, 
which are known as instantaneous water heaters, gas 
water heaters, and automatic instantaneous water 
heaters. The instantaneous water heaters are the 
simplest and least expensive of all gas heaters, and, 
as would be expected, the most restricted in useful- 
ness. Usually, they are used to supply water only 
to the bath tub or to the bath tub and lavatory in a 
bath room, leaving the rest of the building piped 
only for cold water. Nevertheless, this type of 
water heater has its field of usefulness and gives 
good service when installed. 

Gas water heaters of the other type are attached 
to the range boiler, where they take the place of a 



70 



Hot Water for Domestic Use 



waterback ; and automatic instantaneous water heat- 
ers are designed to supply hot water to the entire 
building, day or night, without any care or atten- 
tion from the inmates, and with a consumption of 
gas only when water is being heated. 

Instantaneous Water Heaters. 
A simple apparatus for heating water instantan- 
eously with gas is shown in Fig. 15. In this illus- 
tration part of the cas- 
ing is removed, so the 
interior construction 
may be seen and the 
operation described. 
This apparatus will 
not heat water under 
pressure, but only 
when released from 
pressure and flowing 
over the plates by 
gravity. Owing to 
this fact, the heater 
must be placed at a 
higher elevation than 
the fixture it is intend- 
ed to supply with hot 
water. The operation 
of the heater is as fol- 
lows: A special gas 
that gas cannot be 




Fig. 15. 



cock a is so constructed 



Instantaneous Water Heaters 71 

turned on to the heater without also turning on the 
water valve b, thus preventing the overheating or 
burning of the water heating plates. A pilot light 
c is always burning, so that as soon as the gas and 
water are turned on the gas enters the burners d d 
from the ring e to heat the plate surface. When the 
water is turned on it flows through the valve h 
and up through the standpipe shown in the centre 
of the cylinder, to near the top of the apparatus, 
where it is discharged through a spray nozzle and 
falls in a thin sheet, which spreads out over the 
entire heating surface i. As the water flows over 
this thin metal surface, it absorbs heat from the 
flames and hot gases within, so that by the time it 
reaches the bottom of the compartment and flows 
out of the spout into the bath tub or other fixture, it 
is heated ready for use. A drip-ring / is provided 
near the bottom of the cylinder to catch the drip 
from the beads of moisture which condense on the 
under side of the heating plates. If this drip ring 
were not provided, suflicient water would drain onto 
the floor to keep it damp, rot the woodwork and in 
other ways become a nuisance. 

Instantaneous water heaters are not suitable for 
heating large quantities of water, nor are they de- 
signed to heat any quantity of water to a high tem- 
perature ; their chief usefulness lies in their adapta- 
bility to heat water for bathing purposes, and for 
this use they are often placed in buildings which 



72 Hot Water for Domestic Use 

contain bath rooms, but which are not equipped with 
hot water supply pipes. When used in a bathroom, 
the heater is placed on a shelf near the fixture to be 
supplied, so that the heated water will flow direct by 
gravity into the receptacle. For this purpose they 
are highly satisfactory and may be depended upon 
to give entire satisfaction. Another use to which 
instantaneous water heaters may be put, is to heat 
the water for bathing and washing at camps and 
seaside resorts. If gas is not obtainable in the local- 
ity, by making a few changes the heater can be 
converted into a gasoline-burning water l heater. 
When a heater of this type is located in a bathroom, 
a branch from the discharge tube can be run to 
the wash basin while the main tube discharges into 
the bath tub. By placing a valve or cock in the 
main tube, the water can then be so controlled that 
it may be discharged at will, either into bath tub 
or into lavatory. When the valve is open, the 
water will flow into the bath tub only, and when the 
valve is closed, the water will flow into the wash 
basin. To insure there will be no backing up into 
the basin when the water is wanted at the bath tub, 
the pipe to the basin should be given a slight up- 
ward pitch, so the water will have to rise an inch 
or more to discharge into the basin. Intelligent 
care must be exercised in operating a heater when 
gas is the fuel, for if the cylinder becomes filled 
with gas, there is liable to be a disastrous explosion 
when the gas is ignited. 



Instantaneous Water Heaters. 7Z 

Instantaneous heaters of this description are 
quite economical in the consumption of gas, but 
they are limited in usefulness by the fact that they 
have the capacity to supply only a few fixtures, 
which must be located close together. 




Fig. i6 



Another type of instantaneous water heater is 
shown in Fig. i6. In this heater the water does 
not come in contact with the products of combus- 
tion of the gas, as it does in the type of heater 
previously shown, consequently the heated water 
is much purer and can be used for cooking and 
other purposes, where the heated water will after- 
ward be taken internally. The water in this type 
of heater has its temperature raised while floating 



74 Hot Water for Domestic Use 

through a pipe coil, exposed to the flame of gas 
burners. In the illustration, the casing is shown 
removed, to expose the interior construction of the 
apparatus, so the operation can be explained. Cold 
water enters the coil through the valve e, and the 
flow is regulated by the valve handle h, which con- 
trols both the gas valve and the water valve, so 
that gas cannot be turned on and lighted without 
the water being turned on and the coils filled with 
water. The coils c are so made that the water flows 
immediately to the top row of pipes, and from 
there the coil is graded to where the water dis- 
charges into the fixture through the discharge tube 
d. By this arrangement of the pipe coil, most of 
the heat from the burning gas can be absorbed by 
the water during the brief time required to pass 
through the heater. The reason for this lies in the 
fact that the cold water in the top row of pipes is 
of lower temperature than the hot gases passing 
over them, and as heat travels from the hotter to 
the cooler mediums, a transfer of heat takes place 
from the hot gases to the water within the coils. 
If, instead of the cold water entering the coils at 
the top and discharging from the bottom tier, the 
order were reversed and the cold water entered the 
coil at the bottom and discharged from the top tier, 
the hottest water in the coils would be in the pipes 
at the top, while the coolest gases would likewise 
be found there. As in that case the temperature 



Instantaneous Water Heaters. 75 

of the water within the top pipes of the coil would 
be warmer than the gases passing over them, there 
would be a transfer of heat, but in the inverse order 
from that desired. Instead of heat passing from the 
hot gases to the water, the temperature of the 
water would be lowered by an absorption of heat 
by the gas. 

A supply of gas for the heater is controlled by 
the gas cock e, through which it flows to the burn- 
ers located beneath the coils. A pilot light g 
serves to ignite the burners when hot water is de- 
sired. 

It might seem unnecessary to remark that for 
water heaters, as well as for all other kinds of gas 
apparatus designed to produce heat, some modifica- 
tion of the Bunsen burner should be used. While 
there are from 650 to 700 B. T. U. in one cubic 
foot of illuminating gas, that fact is of no value in 
heating unless almost all of the possible heat is made 
available. This is not possible when burning the 
gas with a yellow flame such as that seen at a gas 
tip, but the possible heat in the gas can be made 
available by means of a blue flame, such as that pro- 
duced by the Bunsen burner, which mixes a certain 
percentage of air with the gas before combustion 
or ignition. Instantaneous water heaters of what- 
ever type can be changed to gasoline water heaters, 
whenever desired. There are many localities, for 
instance in suburban and country residences, where 



76 Hot Water for Domestic Use 

illuminating gas is not available; further, there are 
districts in some small cities where gas mains are 
not laid in the street, and it is well to bear in mind 
that if outside the fire limits of the city instan- 
taneous heaters can be changed so they will be 
available for heating water under such conditions. 
To do so, the gas burners in the heater must be 
changed to gasoline burners, as gasoline cannot be 
burned in an ordinary gas burner. In addition, a 
tank for storing gasoline must be erected some- 
where, preferably outside of the building and a 
pipe connection made between the heater and the 
tank. Wherever the tank is located, and whether 
inside or outside of the building, it must be placed 
at an elevation above the level of the burners in the 
heaters, so that the gasoline will flow to the burners 
by gravity and under slight pressure. 

When gasoline is the fuel to be used, the man- 
ufacturers will change the burners to suit, if, when 
ordering the heater, the plumber will but state that 
he wants the apparatus for burning gasoline. 

The combustion of gas produces a greater or less 
amount of water vapor when the heater is in opera- 
tion. This vapor condenses on the cool under-side 
of the plates or pipes when the water is still cool, 
so that there is usually a slight drip from instan- 
taneous water heaters, even when all the joints, 
pipes and connections are tight. As this drip is 
inseparable from all types of instantaneous water 



Caring for Drip 77 

heaters, they should each be set over a drip pan to 
catch this moisture, and a waste pipe should be pro- 
vided to carry off this condensation. It will not 
do to discharge the drip water through the waste 
pipe into the bath tub or lavatory the heater sup- 
plies, as the water would be very liable to stain the 
fixture. The best way would be to extend the waste 
pipe from the drip pan to a trapped and water-sup- 
plied plain iron sink, which will not be damaged 
by water stains. 

A little practical point which should be remem- 
bered by the plumber when connecting up an in- 
stantaneous water heater is to connect the water 
supply pipe to the heater first. By doing so, no 
damage can result to the heater should the gas be 
turned on and lighted. 

If, on the other hand, the gas were connected to 
the heater first, and through ignorance or malice 
some one were to turn on the gas and light it, the 
plates might be burned, twisted or otherwise dam- 
aged by the heat. When the water is connected to 
the heater first, as it should be, a thin film of water 
is flowing over the plates before the heat strikes 
them, and they are thus protected from damage. 

In addition to the regular combination gas and 
water cock which comes with every heater, a sep- 
arate ground-key stop-cock should be placed both 
in the gas-supply pipe and the water-supply pipe, 
so that the heater can be cut out of service at any 



78 Hot Water for Domestic Use 

time for cleaning or repairs, without necessitating 
the shutting oflf of gas from the entire building, at 
the meter. 

Gas Supply to Water Heaters. 
An instantaneous gas heater will not give good 
service if the gas supply is taken from one of the 
runs in the building, so that when in operation 
the supply of gas to the heater will fluctuate as 
lights are turned on or shut off. What is re- 
quired is an adequate and separate supply of gas 
conducted through a separate gas service of suf- 
ficient size, run from the gas meter direct to the 
water heater. The size of the meter must also be 
taken into account. If the meter is intended to sup- 
ply only the lighting fixtures in the building, it 
will not be large enough to supply both lights and 
heater. A lo-light meter is required for the heater 
alone, and if the supply of gas for the heater is 
taken from the lighting meter, an extra allowance 
of the capacity of a lo-light meter should be pro- 
vided in the house meter. If there is not an ade- 
quate supply of gas to the heater at all times, in 
addition to the decreased heating efficiency of the 
apparatus, there will likewise be the danger of the 
light flashing back in the burners and burning with 
a yellow flame which will produce soot. Indeed, 
one of the chief troubles experienced with instan- 
taneous water heaters is due to this cause. An 
accumulation of soot and lamp black forms from the 



Gas Supply to Water Heaters 79 

light in the burners flashing back and burning that 
way for some time before being discovered. The 
soot thus deposited forms an insulating covering 
over the heating surface, which reduces consider- 
ably the heat transmitted from the burning gas to 
the water, consequently a greater quantity of gas 
must be burned to heat the required amount of 
water. 

With an ample supply of gas furnished under a 
good pressure, ordinarily a l/o"^^^^ S^^ P^P^ wil^ 
provide a suitable supply to an instantaneous water 
heater, provided the distance from the meter to 
the heater is not too great. As an average, it may 
be said that loo feet would not be too great a dis- 
tance for that size of pipe. On the other hand, when 
the supply of gas is scant or the pressure weak the 
service pipe from the meter to the heater should be 
at least ^-inch in diameter. In this case the pipe 
should be run as direct as possible without un- 
necessary bends or offsets, and the distance from 
the meter to the heater should be within loo feet. 

Gas Heaters Must be Vented 

The products of combustion of gas are devoid of 
oxygen, besides containing carbon dioxide and car- 
bon monoxide, which are poisonous. It stands to 
reason, therefore, that these gases should not be per- 
mitted to pour out into the room where the heater 
is located. If, for instance, the heater were located 



80 Capacity of Water Heaters 

in a tightly enclosed bath room, and the gases al- 
lowed to pour out into the room while a bather was 
preparing for the bath, and actually engaged in 
bathing, instead of the refreshed feeling which 
ought to follow the ablution, the bather might leave 
the room feeling weak, dizzy or having a headache, 
if, indeed, in extreme cases he were not asphyx- 
iated. To avoid any such possibility, the combus- 
tion chamber of instantaneous heaters should al- 
way3 be connected with a vent-pipe leading to a 
flue discharging freely into the atmosphere. 

The capacity of instantaneous heaters is much 
greater than would be expected when their use 
is considered. The actual capacity of the heaters 
depends upon the size of the heater and averages 
from about 90 gallons per hour, which is the capac- 
ity of the smallest size, to over 360 gallons per 
hour for the largest size heaters. The water is 
not heated to the boiling point, however, but only 
has the temperature raised high enough for use in 
bathing and other household pursuits, without tem- 
pering with cold water. The capacity of the heater 
is generally rated as raising the temperature of the 
stated quantity of water from ordinary tempera- 
ture, 62° Fahrenheit, to 112° Fahrenheit. 

Some means besides a waterback in the coal 
range is sometimes desirable for heating water in 
range boilers. When such is the case, the most 
natural apparatus to select for the purpose is a spe- 



Special Gas Water Heaters. 



81 



cial gas water heater. Of course a heating coil or 
waterback could be placed in the flame of an ordi- 
nary gas range, but so small a percentage of the heat 

would be utilized that such 
O fl p Q ^ method would prove 

>gC^ ^ii exceedingly expensive as 

^ ^ -^ well as unsatisfactory. 

To fill just such require- 
ments gas water heaters, 
similar to that shown in 
Fig. 17, were designed. Gas 
heaters of this description 
are usually formed either 
with a collection of drop 
tubes, a spiral coil or a spe- 
cial hollow casting of iron 
through which the water 
can flow, and absorb heat 
from the flame and hot 
gases applied to the outside 
of the casting. Whatever 
may be the interior con- 
struction of the water 
heater, it is provided on the 
outside with a casing to 
confine the hot gases in 
close proximity to the hol- 
low casting, so the water 
will have the benefit of all the available heat. The 
heater shown in Fig. 17 is made of cast iron, and in 




Fig. 17. Gas water heater 
for range boiler. 



82 Hot Water for Domestic Use 

the illustration the outer casing is shown raised to 
the top so as to expose the inner casting through 
which the water flows. This casting is placed di- 
rectly above a gas burner so the bottom enlarge- 
ment of the casting will receive the direct heat from 
the flames while the hot gases pass over and around 
the other enlargements, as indicated by the arrows. 
When the casing is down in place the burner is not 
accessible, consequently a pilot light proves con- 
venient for igniting the gas when the water is to 
be heated. Naturally, on account of the great 
amount of gas the heater would consume, it is 
kept in operation only when hot water is required. 
A valve in the gas supply to the heater allows the 
supply to be so regulated that once the water in the 
tank is heated only enough heat need be supplied 
to keep the water at that temperature. It might 
seem needless to add that a Bunsen or atmospheric 
burner is the only kind suitable for such a heater. 
Gas water heaters are placed in the kitchen along- 
side of the tanks to which they are connected. They 
could be placed in the basement, cellar or any other 
part of the house below the level of the boiler, but 
in that case there would be a greater loss of heat, 
the exact amount depending on the distance the 
heater was located away from the hot water tank. 
The best and most convenient place, therefore, to lo- 
cate the heating is in the kitchen, as close as pos- 
sible to the hot water tank. It may then be con- 



Special Gas Water Heaters. 83 

nected up in any approved way, so there will be a 
good circulation of water between the heater and 
the boiler. If desirable, the return pipe from the 
heater can be connected to the side tapping of the 
boiler. It is better practice, though, to extend the 
return pipe to the hot water pipe above the boiler, 
as shown in the illustration. By this means the 
hottest water in the entire system can be drawn 
from the hot water pipes when a faucet is opened. 
In some installations, instead of a separate con- 
nection to the gas water heater, the heater is con- 
nected to the return pipe from the coal range to 
the boiler. This is only done, however, when, in 
large installations, a large hot water tank out of 
proportion to the range and the waterback is used, 
and unless some auxiliary means were provided to 
help heat the water, instead of the waterback doing 
so, the cold water in the boiler would chill the wa- 
terback and spoil the range for cooking and baking 
purposes. In whatever way the heater is used, it 
must be remembered that the cold water pipe must 
be connected to the bottom of the apparatus, and 
the hot water pipe to the top of the apparatus, so 
that as the water is heated in passing through the 
heater, it can follow the natural tendency to rise. 

Further, it is better, when possible, to connect 
the heater to a hot water boiler, independent of 
other connections, and independent of the water- 
back in a coal range. 



84 Hot Water for Domestic Use 

It is unnecessary to place valves in the connec- 
tions to a gas water heater, as when there is no fire 
in the heater there will be little or no circulation 
through the apparatus. It is not only unnecessary 
to use valves, but it is absolutely unwise to do so; 
valves should never be placed in a hot water sys- 
tem when by any possibility they can do harm, and 
if the valves to a gas water heater were shut off 
sufficient pressure would be generated within the 
hollow castings to burst the heater, with perhaps 
disastrous results. 

Gas water heaters are made with sufficient ca- 
pacities to heat the water in boilers of from 30 to 
60 gallons capacity. When larger storage tanks 
than that are used, if this type of heater is selected, 
multiple connections with two or more heaters will 
be required. 

The same trouble will be experienced with gas 
water heaters as is experienced with waterbacks and 
coal water heaters in limestone regions where the 
water supplied to the consumers is hard. Incrusta- 
tions of lime or magnesia will take place inside of 
the hollow casting through which the water flows 
until successive deposits completely obstruct the 
openings, if the lime is not cleaned out before the de- 
posits reach this stage. A gas water heater clogged 
with lime would prove equally as dangerous as if 
connected up to the boiler with valved flow and 
return pipes in which the valves were closed. In 



Special Gas Water Heaters. 85 

addition to the danger liable to arise from the de- 
posit of lime, the efficiency of the heater is vastly 
decreased with each successive deposit, so that far 
more gas will have to be burned to heat a given 
quantity of water than would be required if the 
heating surface were clean. The best remedy for 
preventing clogging of castings or deposits of lime 
is to follow the instructions previously given in 
regard to water-backs. It is a good practice to 
occasionally clean the outside of the water castings 
also, to remove the deposits of soot and lampblack 
deposited whenever the flame flashes back at the 
burner. 

In small kitchens which are poorly ventilated gas 
water heaters should be provided with vent pipes 
to conduct to the outer air the products of com- 
bustion arising from the burning gas. In large, 
well-ventilated kitchens where a separate vent flue 
is provided to carry off the odors of cooking, this 
requirement is not so necessary, although even then 
it is desirable. 



86 



Hot Water for Domestic Use 



Heating Large Bodies of Water. 
Wherever gas water heaters are to be used for 
heating large tanks of water, that is to say, tanks of 
100 gallons and over, the multiple type of heater 

must be used. A compact 
multiple gas water heat- 
er, in which three heaters 
are used, in connection 
with one large hot water 
tank, is shown in Fig. 18. 
In this illustration, part of 
the lower part of the hot 
water tank is broken away 
to show the location of the 
heaters, and the manner of 
connecting them to the 
boiler. As may be seen, 
the heaters are set clover- 
leaf shape, and are snugly 
nested in cavities formed 
within the body of the boil- 
er. From these, cavities, 
vent pipes extend to above 
the top of the tank, so that 
the products of combustion 
can escape. If they could 
not, no hot water could be produced, for the gas 
would refuse to burn in the absence of air or oxygen. 
A good feature of the nesting of gas water heaters 




Fig. 18. Compact multi 
pie gas water heater. 



Thermostatic Control 87 

within the boiler, as is done in this case, lies in the 
fact that there is no loss of heat by radiation from 
the outer surface of the heater casings as there 
would be if these casings were exposed to the at- 
mosphere. AH heat of combustion, even to the ex- 
haust heat in the gases passing up through the vent 
flues, can be transmitted to the water, so that en- 
closed heaters of this type develop the maximum ef- 
ficiency, so far as utilizing all heat contained in the 
gas is concerned. 

It will be noticed that multiple connections con- 
sisting of three-way fittings are used to connect the 
flow pipes from the bottom of the boiler to the bot- 
toms of the heaters, and a like connection is used 
for connecting the return pipes to the top of the boil- 
er. From the top of the multiple connection on top 
of the boiler the hot water supply for the building 
is taken, and from the bottom outlet of the multiple 
connection at the bottom of the boiler an emptying 
pipe can be extended to some suitable place of dis- 
posal. 

To prevent the waste of gas by keeping the heat- 
ers going after the water has been raised to the 
right temperature, a thermostatic arrangement sim- 
ilar to that shown at a may be used. This regu- 
lator, which automatically controls the supply of 
gas, is operated by the temperature of the water 
within the boiler, shutting off the gas when the tem- 
perature of the water reaches a pre-determined 



88 Hot Water for Domestic Use 

point, and turning the gas on again when by use or 
radiation the temperature of the water has again 
been lowered beyond that required. Locating the 
thermostatic tube in the lowest part of the boiler 
insures a good supply of hot water at all times, for, 
when the temperature of the water in the lower part 
of the boiler is cool enough to open the gas cock 
and thus turn on gas to the heater, to heat the water, 
there will be a sufficient supply of hot water in the 
top of the boiler to supply the various fixtures un- 
til the heaters catch up with the demand for hot wa- 
ter. The burners used with multiple heaters are 
of the Bunsen type, and when a thermostat is used, 
they must be provided with pilot lights or other 
means for automatically igniting the gas when it is 
turned on by the thermostat. If there were no 
means for automatically lighting the gas, and the 
flues were connected to chimneys leading to the out- 
er air, gas could escape continuously and no evi- 
dence of the fact would be noticeable within the 
building, and no good would be accomplished by 
the gas. 

Side outlets, b and c, are provided in the hot wa- 
ter tank, so that if desired a water back, special coal 
burning heater or garbage burning water heater 
can also be connected to the tank. 

Automatic Instantaneous Water Heaters. 
In the gas water heaters just considered the heat- 
er does the work of a water back, and a hot water 



Automatic Water Heaters 89 

tank is required to store the hot water in. With 
automatic instantaneous water heaters, on the other 
hand, no boiler or reservoir is necessary, the heater 
supplying the hot water as it is wanted and direct 
to the faucets without the intervention of storage 
devices of any kind. There are many features about 
this type of heater which makes it particularly de- 
sirable for heating water under many conditions. 
The heater can be located in the basement or cellar, 
where the living rooms will not be heated by the 
radiant heat escaping from the heater casing. Gas 
is not consumed keeping hot a large volume of wa- 
ter which is constantly giving off heat to the atmos- 
phere, and fuel is being consumed only when hot 
water is being drawn from a faucet. Having the 
heater located in the basement or cellar, or in some 
other compartment away from the living rooms is 
very desirable in warm climates, whereas in cold 
parts of the country the additional heat might prove 
very acceptable in the kitchen. When such is the 
case an automatic instantaneous water heater may 
be located in the kitchen, or a gas water heater with 
storage tank used, both to heat water and keep the 
kitchen warm. 

The greatest use for the automatic instantaneous 
heaters is found in modern residences, where the 
effort is made to provide both comfort and conven- 
ience in the kitchen. In these buildings gas ranges 
are substituted for coal ranges, so the kitchen will 



90 



Hot Water for Domestic Use 



be cool in the summer time, and radiators or regis- 
ters, as the case may be, are provided to heat the 
kitchen in the winter. 




Fig. 19. Sketch showing interior construction of an 
instantaneous automatic water heater. 

An instantaneous automatic water heater is shown 
in Fig. 19. In this illustration the doors are open 



Automatic Water Heaters 91 

to show the interior construction of the apparatus. 
The heater consists simply of several coils of copper 
pipe, occupying the space inside of a casing and 
placed immediately over a cluster of Bunsen burn- 
ers. By this construction, most of the heat devel- 
oped by the combustion of the gas is absorbed by 
the water coils and transmitted to the water. The 
heater is also provided with a combination automatic 
gas and water cock, to control and regulate the flow 
of gas and water, and a thermostat to shut off the 
supply of gas, but still leave the water flow, when 
the temperature of the water flowing through the 
coils exceeds a certain temperature. 

The operation of the heaters is very simple. They 
are set up in the basement, cellar or any other con- 
venient part of the building and the cold water sup- 
ply is connected to them in such a way that all water 
flowing to the hot water faucets in the building will 
first have to flow through the coils in the heater. 
After the water pipe in the apparatus is ready for 
service, all that is necessary then, after the pilot 
light has been started, is to open a hot water faucet 
in any part of the building, and hot water will be 
drawn as long as the faucet is kept open. The im- 
portant part of heaters of this class is the automatic 
gas and water cock, which regulates the flow of gas 
and water respectively through the gas and water 
service pipes. The apparatus is operated really by 
the pressure of water in the water pipe. A pilot 



92 Hot Water for Domestic Use 

light attached to the gas service and located within 
the heater in close proximity to the cluster of Bun- 
sen burners is always burning; then, as soon as a 
hot water faucet anj^where in the building is opened, 
the pressure is correspondingly relieved from the 
automatic valve. This immediately permits the es- 
cape of gas through the water regulated gas valve, 
which is ignited by the pilot light, and the flames 
and hot gases heat the water in the coils. This 
water controlled gas and water valve is unique in 
that the gas and water are adjusted to each other 
in such a way that the flow of water through the 
copper coils is proportioned to the amount of gas 
which is being consumed, so that just sufficient gas 
is consumed to heat the water required. That is to 
say, if the water is flowing through the copper coils 
in the heater at the rate of three gallons per min- 
ute, the consumption of gas is at the rate of three 
cubic feet per minute, which is just sufficient to heat 
the three gallons of water from ordinary tempera- 
ture to about 130° Fahrenheit, which is about the 
right temperature for domestic water supply. If, 
on the other hand, water is flowing through the 
copper coils in the heater at the rate of six gallons 
per minute the gas will be consumed at the rate of 
six cubic feet per minute. By this nice adjustment 
of gas and water to each other there is no waste of 
gas heating a larger quantity of water than is re- 
quired, or a smaller quantity of water to a higher 
temperature than is wanted. 



Thermostatic Control 93 

In order to be able to heat the largest quantity of 
water which they are rated to as fast as the water 
might flow through the coils there is not only a 
large amount of heating surface in the coils, but 
there are likewise a number of burners in the clus- 
ter — so many, in fact, that if the gas from these 
were allowed to burn continuously the water would 
be heated to far above the desired temperature. To 
prevent this a thermostat is provided, and the ac- 
tion of the gas burners is intermittent. 

The thermostats are provided with an expansive 
metal rod or some equally sensitive operating device, 
which is in contact with the water flowing through 
the coils, and the thermostat is so regulated that 
when the temperature of the water reaches a cer- 
tain degree the operation of the thermostat will cut 
oflf the supply of gas from all burners but the pilot 
light. This immediately removes the source of heat, 
but the water still continues to be warmed by the 
hot gases remaining in the combustion chamber 
and the heat stored in the coils, until sufficient cold 
water has been run through the apparatus to absorb 
this heat. As soon as it does the lowered tempera- 
ture of the water causes the gas valve to open; the 
gas is immediately ignited by the pilot light and the 
maximum heat is again available in the heater. 

Unless ordered otherwise, the thermostat on auto- 
matic instantaneous heaters is regulated to shut off 
the gas when the temperature of the water reaches 



94 Hot Water for Domestic Use 

140° Fahrenheit. Raising the water to 135 or 
140° temperature allows for its being delivered at 
the fixtures at about 130° temperature, according to 
the distance the water must travel after leaving the 
heater and before reaching the faucet. The only 
loss is that due to radiation and maintaining the 
temperature of the hot water, but this might amount 
to a considerable sum if the runs are long and the 
pipes uncovered and exposed in cold places. To 
economize on operating expenses the hot water sup- 
ply pipes from a gas heater of the pressure type 
should be well protected with an insulating covering 
to prevent the loss of heat. 

As ordinarily constructed, automatic instantane- 
ous heaters are rated to heat from ordinary temper- 
ature to 130° Fahrenheit, one gallon of water for 
each cubic foot of gas consumed; that is, pro- 
vided the gas tests over 700 British thermal units. 
Generally, however, the heaters are rated to possess 
capacities capable of raising one gallon of water 62^ 
Fahrenheit, with the consum.ption of one cubic 
foot of gas testing 650 heat units. 

Automatic instantaneous water heaters would not 
prove economical for heating large quantities of 
water for hotels, apartment houses, asylums, sani- 
tariums, hospitals or other large buildings where 
the runs of pipe would be long; consequently they 
are not made wath larger capacities than are re- 
quired for private houses. The heaters are made in 



Comparative Cost 95 

three sizes, the smallest of which has the capacity 
to raise the temperature of three gallons of water 
50° Fahrenheit per minute, with a consumption of 
three cubic feet of gas, and the largest possesses a 
capacity of seven gallons of water per minute, raised 
50° Fahrenheit, with a consumption of seven cubic 
feet of gas. The smallest size is intended for build- 
ings having one bathroom, and the largest for build- 
ings having not over four bathrooms. 

Automatic instantaneous water heaters would 
prove objectionable in buildings where large quanti- 
ties of water must be heated, not only on account of 
the greater cost of heating water with gas over that 
of coal when large quantities are to be continuously 
heated, but for the additional reasons that circula- 
tion of hot water could not be economically main- 
tained throughout the building; consequently the 
hot water pipes would stand full of cold water, 
which would have to be drawn off and the pipes 
heated before hot water could be drawn at a faucet, 
whereas in a properly constructed hot water installa- 
tion in a hotel or like building hot water should be 
drawn from the faucet the instant it is opened. 

It might be well to add in passing that circula- 
tion of hot water throughout the building cannot be 
economically maintained in large buildings where 
any type of pressure gas water heater is used. 



96 Hot Watek for Domestic Use 



USE OF STEAM FOR HEATING WATER. 

Of all means for heating water there is none so 
convenient as steam, when a plentiful supply is 
available for that purpose. So fully is this princi- 
ple recognized that steam is used for a multitude 
of purposes when heat must be applied to liquids. 
One feature of heating water with steam which is 
valuable in many instances is the fact that by regu- 
lating the temperature of the steam any desired de- 
gree of heat may be maintained and at a uniform 
temperature. Advantage is taken of this fact in 
canning factories, soap manufactories, as well as 
in hotels and institutions, such as hospitals and 
asylums, and kettles with steam jackets are used in 
the preparation of meals and steam coils used for 
heating water for the various domestic purposes. 

The convenience of steam and its entire absence 
of danger or odors which must be safely conducted 
out of doors are other factors which make steam a 
very desirable medium for heating water. Once 
the steam connection is made there is no attention 
required other than turning on or shutting oflf the 
steam valves, and even this attention may be dis- 
pensed with where water must be kept continuously 
warm, as, for instance, in storage tanks for hot 
water, by using an automatic temperature regulator 



Properties of Steam 



97 



TABLE VII-PROPERTIES OF SATURATED STEAM 













Weight 


Volume 






Heat Units above 32 Degrees 


of 


of 




Tempera- 




Fahr. 




1 Cubic 


1 Pound 




ture 


Contained in 1 Pound of Steam 


Foot 


In 


Absolute 


Degrees 




Latent 


Total 


In 


Cubic 


rressnre 


Fahr. 


In Water 


Heat 


Heat 


Pounds 


Feet 


14.7 


212.0 


180.9 


965.7 


1146.6 


.0379 


26.37 


15 


213.1 


181.6 


965.3 


.9 


.0387 


25.85 


16 


216.3 


184.9 


963.0 


1147.9 


.0411 


24.33 


17 


219.5 


188.1 


960.8 


1148.9 


.0435 


22.98 


18 


222.4 


191.1 


958.7 


1149.8 


.0459 


21.78 


19 


225.8 


193.9 


956.7 


1150.6 


.0483 


20.70 


20 


228.0 


198.7 


951.8 


1151.5 


.0507 


19.73 


21 


230.6 


199.3 


953.0 


1152.3 


.0531 


18.84 


22 


233.1 


201.8 


951.2 


1153.0 


.0554 


18.04 


23 


235.5 


204.3 


949.5 


.8 


.0578 


17.30 


24 


237.8 


206.6 


947.9 


1154.5 


.0602 


16.62 


25 


240.1 


208.9 


946.3 


1155.2 


.0625 


16.00 


26 


242.2 


211.1 


944.7 


.8 


.0649 


15.42 


27 


244.3 


213.2 


943.3 


1156.5 


.0672 


14.88 


28 


246.4 


215.3 


941.8 


1157.1 


.0695 


14.38 


29 


248.4 


217.8 


940.4 


.7 


.0719 


13.91 


30 


250.3 


219.3 


939.0 


1158.3 


.0742 


13.48 


31 


252.2 


221.2 


937.7 


.9 


.0765 


13.07 


S2 


254.0 


223.0 


936.4 


1159.4 


.0788 


12.68 


33 


255.8 


224.8 


935.1 


.9 


.0812 


12.32 


34 


257.5 


226.6 


933.9 


1160.5 


.0835 


11.98 


35 


259.2 


228.3 


932.7 


1161.0 


.0858 


11.66 


?.6 


260.9 


230.0 


931.5 


.5 


.0881 


11.36 


37 


262.5 


231.6 


930.4 


1162.0 


.0904 


11.07 


38 


264.1 


233.3 


929.2 


.5 


.0927 


10.79 


39 


265.6 


2.34.8 


928.1 


.9 


.0949 


10.53 


40 


207.2 


236.4 


927.0 


1163.4 


.0972 


10.28 


41 


268.7 


237.9 


926.0 


.9 


.0995 


10.05 


42 


270.1 


239.4 


924.9 


1164.3 


.1018 


9.83 


43 


271.6 


240.8 


923.9 


.7 


.1041 


9.61 


44 


273.0 


242.3 


922.9 


1165.2 


.1063 


9.40 


45 


274.3 


243.7 


921.9 


.6 


.1086 


9.21 


46 


275.7 


245.1 


920.9 


1166.0 


.1109 


9.02 


47 


277.0 


246.4 


920.0 


.4 


.1131 


8.84 


4S 


278.3 


247.7 


919.1 


.8 


.1154 


8.67 


40 


279.6 


249.1 


918.1 


1167.2 


.1177 


8.50 


50 


2S0.9 


250.3 


917.3 


.6 


.1199 


8.34 


51 


2S2.2 


251.6 


916.4 


1168.0 


.1222 


8.19 


52 


283.4 


252.9 


915.5 


.4 


.1244 


8.04 


53 


284.6 


254.1 


914.6 


.7 


.1267 


7.89 


54 


285.8 


255.3 


913.8 


1169.1 


.1289 


7.76 


55 


287.0 


256.5 


912.9 


.4 


.1312 


7.62 


56 


288.1 


2.57.7 


912.1 


1169.8 


.1334 


7.50 


57 


2S9.S 


25S.9 


911.3 


1170.2 


.1357 


7.37 


58 


290.4 


260.0 


910.5 


.5 


.1379 


7.25 


59 


291.5 


261.1 


909.7 


.8 


.1401 


7.14 



98 



Hot Water for Domestic Use 



TABLE VII— Continued. 













Weight 


Volume 






Heat Units above 32 Degrees 


of 


of 




Tempera- 




Fahr. 




1 Cubic 


1 Pound 




ture 


Contained 


in 1 Pound of Steam 


Foot 


In 


Absolute 


De2:rees 




Latent 


Total 


in 


Cubic 


Pressure 


Falir. 


In Water 


Heat 


Heat 


Pounds 


Feet 


60 


292.6 


262.3 


908.9 


1171.2 


.1424 


7.02 


61 


293.7 


263.3 


90S.2 


.5 


.1446 


6.92 


62 


294.7 


264.4 


907.4 


.8 


.1468 


6.81 


63 


295.8 


265.5 


906.6 


1172.1 


.1491 


6.71 


64 


296.8 


266.6 


905.9 


.5 


.1513 


6.61 


65 


297.8 


267.6 


905.2 


.8 


.1535 


6.52 


66 


298.8 


268.7 


904.4 


1173.1 


.1557 


6.42 


67 


299.8 


269.7 


903.7 


.4 


.1579 


6.33 


68 


300.8 


270.7 


903.0 


.7 


.1602 


6.24 


69 


301.8 


271.7 


902.3 


1174.0 


.1624 


6.16 


70 


302.8 


272.7 


001.6 


.3 


.1646 


6.08 


71 


303.7 


273.6 


901.0 


.6 


.1668 


6.00 


72 


304.7 


274.6 


900.3 


.9 


.1690 


5.92 


73 


305.6 


275.6 


899. 6 


1175.2 


,1712 


5.84 


74 


306.5 


276.5 


898.9 


.4 


.1734 


5.77 


75 


307.4 


277.4 


898.3 


.7 


.1756 


5.69 


76 


308.3 


278.4 


897.6 


1176.0 


.1778 


5.62 


77 


309.2 


279.3 


897.0 , 


.3 


.1800 


5.56 


78 


310.1 


280.2 


896.3 


.5 


.1822 


5.49 


79 


3n.o 


281.1 


895.7 


.8 


.1844 


5.42 


80 


311.9 


282.0 


895.1 


1177.1 


.1866 


5.36 


81 


3J2.7 


282.8 


894.5 


.3 


.1888 


5.30 


82 


313.6 


283.7 


893.9 


.6 


.1910 


5.24 


83 


314.4 


284.5 


893.3 


.8 


.1932 


5.18 


84 


315.3 


285.4 


892.7 


1178.1 


.1954 


5.12 


85 


316.1 


286.2 


892.1 


.3 


.1976 


5.06 


86 


316.9 


287.1 


891.5 


.6 


.1998 


5.01 


87 


317.7 


287.9 


890.9 


.8 


.2020 


4.95 


88 


318.5 


288.8 


890.3 


1179.1 


.2042 


4.90 


89 


319.3 


289.6 


889.7 


.3 


.2063 


4.85 


90 


320.1 


290.4 


889.2 


.6 


.2085 


4.80 


91 


320.9 


291.2 


888.6 


.8 


.2107 


4.75 


92 


321.7 


291.9 


888.1 


1180.0 


.2129 


4.70 


93 


322.4 


292.8 


887. 5 


.3 


.2151 


4.65 


94 


323.2 


293.5 


887.0 


.5 


.2173 


4.60 


95 


323.9 


294.3 


886.4 


.7 


.2194 


4.56 


96 


324.7 


295.1 


885.9 


1181.0 


.2216 


4.51 


97 


325.4 


295.8 


885.4 


.2 


.2238 


4.47 


98 


326.2 


296.6 


884.8 


.4 


.2260 


4.43 


99 


326.9 


297.3 


884.3 


.6 


.2281 


4.38 


100 


327.6 


298.1 


883.8 


.9 


.2303 


4.34 


101 


328.3 


298.8 


883.3 


1132.1 


.2325 


4.30 


102 


329.1 


296.6 


882.7 


.3 


.2346 


4.26 


103 


329.8 


300.3 


882.2 


.5 


.2368 


4.22 


104 


330.5 


301.0 


881.7 


.7 


.2390 


4.19 


105 


331.2 


301.7 


881.2 


.9 


.2411 


4.15 


106 


331.9 


302.4 


880.7 


1183.1 


.2433 


4.11 


m? 


332.6 


30.3 2 


880 2 


.4 


.2455 


4.07 



Properties of Steam 
table vii-continued. 



99 













Weight 


Volume 






Heat Units above 32 Degrees 


of 


of 




Tempera- 




Fahr. 




1 Cubic 


1 Pound 




ti4re 


Contained in 1 Pound of Steam 


Foot 


In 


Absolute 


Degrees 




Latent 


Total 


in 


Cubic 


rressure 


Fahr. 


In Water 


Heat 


Heat 


Pounds 


Feet 


108 


S33.2 


303.9 


879.7 


1183.6 


.2476 


4.04 


109 


333.9 


304.6 


879.2 


.8 


.2498 


4.00 


110 


334.6 


305.3 


878.7 


1184.0 


.2519 


3.97 


111 


335.3 


305.9 


878.3 


.2 


.2541 


3.94 


112 


335.9 


306.6 


877.8 


1184.4 


.2563 


3.90 


113 


336.6 


307.3 


877.3 


.6 


.2584 


3.87 


114 


337.2 


308.0 


876.8 


.8 


.2606 


3.84 


115 


337.9 


308.6 


876.4 


1185.0 


.2627 


3.81 


116 


33S.5 


309.3 


875.9 


.2 


.2649 


3.78 


117 


339.2 


310.0 


875.4 


.4 


.2670 


3.75 


118 


339.8 


310.6 


875.0 


.6 


.2692 


3.72 


119 


340.4 


311.3 


874.5 


.8 


.2713 


3.69 


120 


341.1 


311.9 


874.1 


1186.0 


.2735 


3.66 


121 


341.7 


312.5 


873.6 


.1 


.2757 


3.63 


122 


342.3 


313.1 


873.2 


.3 


.2778 


3.60 


123 


342.9 


313.8 


872.7 


.5 


.2799 


3.57 


124 


343.5 


314.4 


872.3 


.7 


.2821 


3.55 


125 


344.1 


310.1 


871.8 


.9 


.2842 


3.52 


126 


344.7 


315.7 


871.4 


1187.1 


.2864 


3.49 


127 


345.3 


316.3 


871.0 


.3 


.2885 


3.47 


128 


345.9 


316.9 


870.5 


.4 


.2907 


3.44 


129 


346.5 


317.5 


870.1 


.6 


.2928 


3.42 


130 


347.1 


318.1 


869.7 


.8 


.2950 


3.30 


131 


347.7 


318.7 


869.3 


1188.0 


.2971 


3.37 


132 


348.3 


319.3 


86S.9 


.2 


.2992 


3.34 


133 


348.9 


319.9 


868.4 


.3 


.3014 


3.32 


134 


349.4 


320.5 


868.0 


.5 


.3035 


3.30 


135 


350.0 


321.1 


867.6 


.7 


.3057 


3.27 


136 


350.6 


321.7 


867.2 


.9 


.3078 


3.25 


137 


351.1 


322.3 


860.8 


11S9.1 


.3099 


3.23 


ISO 


351.7 


322.8 


866.4 


.2 


.3121 


3.20 


139 


352.3 


323.4 


866.0 


.4 


.3142 


3.18 


140 


352.8 


324.0 


865.6 


.6 


.3163 


3.16 


141 


353.4 


324.6 


865.1 


.7 


.3185 


3.14 


142 


353.9 


325.1 


864.8 


.9 


.3206 


3.12 


143 


354.5 


325.7 


864.4 


1190.1 


.3227 


3.10 


144 


355.0 


326.2 


864.0 


.2 


.3249 


3.08 


145 


355.6 


326. S 


863.6 


.4 


.3270 


3.06 


146 


35G.1 


327.4 


863.2 


.6 


.3291 


3.04 


147 


356.6 


327.9 


862.8 


.7 


.3313 


3.02 


148 


357.2 


328.5 


862.4 


.9 


.3334 


3.00 


149 


357.7 


329.0 


862.0 


1191.0 


.3355 


3.98 


150 


358.2 


329.6 


861.6 


.2 


.3376 


2.96 


160 


363.3 


334.9 


857.9 


1192.8 


.3589 


2.79 


170 


368.2 


339.9 


854.4 


1194.3 


.3801 


2.63 


180 


372.9 


344.7 


851.0 


1195.7 


.4012 


2.49 


190 


377.4 


349.3 


847.7 


1197.0 


.4223 


2.37 


200 


381.6 


353.7 


844.6 


1198.3 


.4433 


2.26 



100 Hot Water for Domestic Use 

to cut off the steam when the water reaches a cer- 
tain temperature. 

In large institutions steam under pressure of at 
least 80 pounds per square inch is available, and 
in factories even higher pressures than 80 pounds 
are maintained. But assuming that a pressure of 
80 pounds gauge pressure is all that is available, 
with such a pressure the temperature of the steam 
would be 323 degrees Fahrenheit, so that water 
could be quickly boiled by means of steam at such 
a high temperature. If, on the other hand, steam 
with a temperature no higher than that of boiling 
water is desired, there is usually enough exhaust 
steam available around an institution to use for this 
purpose. If not, by means of a pressure reducer, 
the pressure can be brought down to correspond 
with the temperature desired. When the pressure 
of the available steam is known the corresponding 
temperature can be found in Table VII. In this ta- 
ble may also be found the heat units above 32 de- 
grees Fahrenheit contained in one pound of steam 
at the various temperatures, the weight in pounds 
of one cubic foot of steam at the various pressures 
and the volume or space in cubic feet occupied by 
one pound of steam at the various pressures. For 
instance, it will be found that a pound of steam at 
an absolute pressure of 14.7 pounds, which occupies 



Steam Connections 101 

26.37 cubic feet at iii pounds pressure absolute, 
occupies only 3.94 cubic feet of space. 

There is a great deal of valuable information in 
this table, with which the plumber should make him- 
self familiar, as a thorough understanding of the 
various data contained will make simple many prob- 
lems of hot-water heating. In applying the table 
it must be remembered that the pressures are given 
as absolute pressures. To convert them into gauge 
pressures 14.7 pounds m.ust be subtracted from 
each absolute pressure reading. For instance, the 
first item in the table is 14.7 pounds absolute pres- 
sure. That means that while steam is forming in a 
boiler no pressure would be indicated on the pres- 
sure gauge, and that the temperature of the steam 
and water in contact would be 212 degrees Fahren- 
heit. 

Steam Connections to Range Boilers. 

Steam is sometimes available, so it can be used 
for heating the water in range boilers for domes- 
tic use. At other times the steam is available only 
during the cold months of the year, and during the 
rest of the time the water must be heated in a 
waterback, coil or gas heater. When the water in 
a range boiler is to be heated with steam a special 
steam coil must be placed in the boiler, and this 
must be done before the bottom end is riveted into 
the boiler. A kitchen range boiler fitted with a 



102 



Hot Water for Domestic Use 






steam coil is shown in perspective in Fig. 20. In this 
illustration part of the lower portion of the plate is 
broken away to show the location and construction 
of the steam coil. The 
coil is simply a spiral of 
pipe, which is fitted snugly in- 
side of the boiler and has the 
two ends projecting through 
the side of the boiler plate, so 
they can be connected to the 
steam and return pipes. It 
will be noticed that the coil 
grades downward from where 
it enters the top opening to the 
boiler to where the other end 
is again returned to the out- 
side of the tank. The reason 
for this is so that water from 
the steam which is condensed 
in the coil can flow naturally 
by gravity to the natural out- 
let. If the coil were trapped 
at any point water of condensa- 
tion would be retained in the 
and cause a rattling, snapping sound within the 
boiler, besides interfering with the free circulation 
of steam through the coil. 

It will further be observed that the steam coil 
is located at the bottom of the range boiler. If it 




Fig. 20. Range 
boUer fitted with 
steam coil. 



Steam Connections 103 

were not located at the bottom the capacity of the 
boiler would be cut down in direct proportion to the 
distance of the coil from the bottom. It will be 
remembered that at all ordinary temperatures wa- 
ter expands and becomes lighter upon being heated. 
That being true, if the coil be located at the bot- 
tom of the tank when the steam is turned on the 
water which is in contact with the coil will become 
hot, expand and rise to the top of the boiler, while 
its place is occupied by a cold current of water flow- 
ing down along the sides of the boiler, thus setting 
up a local circulation throughout the entire con- 
tents of the tank. If, now, instead of locating the 
coil at the bottom of the tank it were placed near 
the top, the water in contact with the coil would be- 
come hot, expand and rise to the top of the tank, 
as in the first instance, but the local circulation set 
up would not go any deeper than the bottom of the 
coil, while the water below that level might be 
actually cold when the water at the top of the boil- 
er was boiling. It will thus be seen that the loca- 
tion of the steam coil in a range boiler has a marked 
influence on the capacity of the boiler. 

The steam supply to the heating coil in a boiler 
should be connected to the upper inlet to the coil 
and the return pipe should be connected to the lower 
inlet to the coil. Valves should be placed both on 
the steam pipe and the return pipe, so steam can 
be cut oflf from the boiler at anv time. A steam coil 



104 Hot Water for Domestic Use 

in a range boiler does not interfere with the ordinary 
outlets to the boiler, which are left in condition 
to be connected up to a range waterback or gas 
heater. When ordering a range boiler with a steam 
coil it is well, however, to state just where the 
steam and return connections shall project through 
the shell. It is better practice still to send a sketch 
showing size and location of the outlets to the coil. 
Almost any kind of tubing used in plumbing work 
may be made up into a steam coil for range boilers, 
but on account of the greater capacity to transmit 
heat possessed by copper over other metals copper 
coils are generally used for this purpose. The cop- 
per pipe is seamless drawn tubing of iron pipe size, 
and is fully as strong as wrought pipe. 

Heating Water With Live Steam. 

Live steam is used for heating water principally 
in hotels and large institutions where steam is re- 
quired for power throughout the entire year. It is 
utilized by passing the steam through steam coils, 
submerged in the water to be heated. Large spe- 
cial storage tanks are provided for the storage of 
the hot water, and the steam coils are placed inside 
of these tanks. When vertical tanks are used a spi- 
ral coil, similar to the one used in range boilers, is 
placed in the tanks. However, in most buildings 
horizontal tanks are used, as they can easily be 
suspended from the ceiling beams, thus leaving the 



Steam Connections 



105 



floor space beneath free for other uses. When hor- 
izontal tanks are used a different type of coil is 
generally used, although a spiral coil would be avail- 
able for the purpose. 

A horizontal tank, fitted with a steam coil for 
the circulation of live steam, is shown in Fig. 21. 
In this form of construction the coil occupied a 
vertical position in the centre of the tank, with the 
lowest pipe of the coil close to the bottom of the 
tank. The coil which is made up with return 
bends, is held in place by means of two supports, 
designed to stay the pipes and keep them from get- 
ting out of place. The live steam pipe is connected 
to the pipe of the coil at a and circulates through 
the entire length of the combined pipes, parting 





^ 



Fig. 21. A horizontal tank fitted with coil for live steam. 

with its heat as it passes along, until, condensed to 
water, it finally passes out through the bottom pipe 
of the coil into the return connection which is at- 
tached at b. The value of having a coil of this de- 



106 Hot Water for Domestic Use 

scription in a tank, instead of grouping all of the 
pipes together near the bottom, lies in the fact that 
the condensed steam can be cooled to a lower tem- 
perature, or in other words will impart more of its 
heat to the water. The coldest part of the water 
is in the lowest part of the tank, and so long as the 
water there is not hotter than the water of con- 
densation within the coil, it will absorb more heat 
from the condensed steam until the temperature 
of the water within the coil, and that in the tank 
outside, are about at the same degrees. 

The hot water connection to this tank is taken 
oflf at Cy from the top of the tank where the hottest 
water is stored, and the cold water pipe is con- 
nected to the tank at d. The cold water pipe could 
be connected to the top of the tank the same as for 
the cold water connection to a range boiler, but in 
that case a tube would have to be continued dowm 
to near the bottom of the tank. If a circulation 
pipe is used in the building where water is heated 
with live steam in a coil, as shown in the illustra- 
tion, the return or circulating pipe should be con- 
nected to the bottom side of the tank, or to one of 
the ends but very low down. In order that the 
coil may be placed in a hot water tank and so that 
the coil will afterwards be accessible for alterations 
and repairs a manhole should be provided in one 
of the ends, to the tank. At e in the illustration 
is shown the yoke which holds the manhole cover 



Heating by Exhaust Steam 107 

for this tank in place. It will be noticed that the 
opening is large enough to permit a man to enter 
the tank. 

Heating Water With Exhaust Steam. 
When steam has done useful work, expansively, 
by being expanded in the cylinder of an engine or 
pump, it still is capable of doing useful work by 
parting with the heat it still contains. To utilize 
this heat, which would otherwise be wasted, special 
coils are made for horizontal tanks, so that water 
can be heated with exhaust steam. It is desirable 
in heating with exhaust steam that as little back 
pressure as possible be put on the cylinders from 
which the steam is taken, otherwise the reduced 
power of the engines would more than offset the 
saving effected by using the exhaust steam for 
heating purpose. In order that but little resistance 
will be offered when steam flows through the coils 
of an exhaust steam hot water tank, the pipes are 
made larger than when live steam is used, bends 
are made instead of using elbows and return bends, 
and special headers or manifold fittings are used 
so the steam and water of condensation will not 
have to travel continuously through the entire coil. 
With these provisions observed, exhaust steam 
proves, within limited temperatures, as good a 
medium as live steam for heating water, and pos- 
sesses the additional advantage in its favor that 
the cost of the steam is practically nothing, as, if 



108 



Hot Water for Domestic Use 



it were not used for that purpose, the heat and 
vapor would be wasted. Exhaust steam on the 
other hand, is open to the objection that it cannot 
heat water to a greater temperature than 212 de- 
grees Fahrenheit, while live steam under pressure 
on the contrary can heat water as high as 300 de- 
grees Fahrenheit. 

A hot water tank fitted with a coil for the use 
of exhaust steam, is shown in section in Fig. 22. 




^Drfp P/pe. 



Fig. 22. 



A hot water tank fitted with a coil for exhaust 
steam. 

This tank may be used either as a hot water stor- 
age tank to supply hot water to a building or as a 
tank for cooling exhaust steam where it must be 
discharged into the sewer, or in some other place 
where the puffing of steam would be objectionable. 
The hot and cold water connections to the tank, 
likewise the circulation connections, should be made 
in the same manner as if the tank were heated with 
live steam flowing through the coils, for the water 
supply part of both tanks are identical and they 



Steam Coils 109 

differ only in the construction of the steam coils. 
All the principal features of an exhaust steam heat- 
ing coil are shown plainly in the illustration. The 
inlet or exhaust pipe from the pump or engine is 
connected to the coil at a; from the enlarged 
chamber within the head casting, the exhaust steam 
can pass through any one of the three pipes shown, 
to the outlet chamber on the lower side of the tank, 
to which i? connected the outlet pipe b. It will be 
noticed that the coils are made up without fittings, 
long sweeping pipe bends taking the place of re- 
turn bends in ordinary coil construction. 

It might be well to point out that while exhaust 
steam cannot well be used in a coil made for high- 
pressure live steam, live steam can safely be used 
in coils made for exhaust steam pressure. It 
should likewise be remembered that as the coil 
placed in a hot water tank for heating the water 
with exhaust steam is designed to heat the water 
with steam at 212 degrees Fahrenheit, when high 
pressure steam of 300 or more degrees Fahrenheit 
is used, the water will be made much hotter than is 
desirable. This, of course can be prevented by re- 
ducing the live steam, to about atmospheric pres- 
sure before discharging it into the exhaust steam 
coil. It is good practice when fitting up a hot 
water tank to be heated with exhaust steam to 
also make a connection of live steam to the coil so 
that live steam can be turned on to keep the water 



110 Hot Water for Domestic Use 

warm if it ever becomes necessary to shut down the 
pump or engine for repairs. 

Steam coils for hot water tanks may be made of 
any suitable materials. Generally, however, they 
are made of copper, brass or wrought pipe. Cop- 
per and brass pipes will last longer than wrought 
pipes, which are liable to corrode through in a 
very short time and furthermore, they will trans- 
mit more heat to the water per square foot of heat- 
ing surface or lineal foot of pipe. For these rea- 
sons, either copper pipe or brass pipe is preferable 
to iron pipe for steam coils in tanks. 

The amount of heating surface required in a 
steam coil for heating water in a tank is a matter 
of importance to the plumber or fitter who installs 
the plant. Roughly, it may be said that the pro- 
portion of heating surface to the capacity of the 
tank should be about i to lo. That is to say, for 
every lo gallons capacity of the tank, there should 
be one foot of heating surface in the coil. If the 
heating coil be made up of i inch pipe, the size of 
the coil can be proportioned, by allowing 3^ lineal 
feet of the pipe for every 10 gallons of water to 
be heated. 

Heating Water With Steam in Contact. 

One of the simplest and best methods for heat- 
ing water with live steam, is to bring the steam 
into direct contact with the water to be heated, in- 
stead of causing it to circulate through pipe coils. 



Heating Open Tanks 111 

submerged in the water. The reason that this is a 
good method hes in the fact that it is the quickest, 
the steam parting with its heat to the water almost 
instantaneously, and the method is economical as 
it requires no submerged coils or other expensive 
apparatus. Owing to some disadvantages of this 
method of heating water it is not used in do- 
mestic practice but finds its greatest field of 
usefulness in industrial plants heating large 
vats of water. It likewise is extensively 
used to heat water in swimming pools, and 
for heating water for dish washing in 
^hotels, restaurants andf large institutions 
where many dishes are soiled every day. 



o o ♦ / ^ » ♦ * g J w 

^ • • ^ • • 5 • . • 'I "m • 5 _■•■ • • • • • • ^ * I I 



Pig. 23. Shows how steam can be piped into a tank o/ 

water. 

The usual method of bringing the steam into 
contact with the water is to force it through a 
perforated pipe, located near the bottom of the 
tank, and covered with water. The manner of 



112 Hot Water for Domestic Use 

piping the steam into the tank of water is shown in 
Fig. 23. A capped and perforated pipe a, is illus- 
trated submerged in a tank of liquid. The perfor- 
ated pipe which is raised slightly above the bottom 
of the tank, to permit the escape of steam from all 
sides, is connected to the vertical line of pipe which 
is valved to control the supply of steam and per- 
mit it to be turned off or on at will, by the attend- 
ant. If the tank is a large one, instead of a single 
perforated pipe, a number of them may be con- 
nected to a manifold header supplied with steam 
from a large pipe having a capacity of the three 
smaller ones. 

In order that the steam may escape freely and 
with the pressure sufficiently reduced so it will not 
be carried direct to the surface of the water in the 
tank, the escape pipes should be liberally supplied 
with perforations. To insure the best results the 
combined area of the perforations should be equal 
to 8 times the area of the perforated pipe to equal 
it in capacity. Ordinarily the individual perfora- 
tions need not be very large. In brass or copper 
pipe, or in any other medium which is not liable to 
become obstructed by a formation of rust or other 
deposits the perforations need not be over }i- 
inch in diameter. In very large vats, however, 
heated with steam discharged through very large 
pipes, the perforations may be from j4-i^<^h to ^- 
inch in diameter. 



Heating Water by Steam 113 

Copper and brass are suitable materials for per- 
forated pipes, when used for heating pure water, 
or liquors which contain no acids injurious to those 
materials. When, however liquids containing acids 
are to be heated, a metal, alloy, or other substance 
which will withstand the action of the acid must 
be selected. Tubing made of Tobin Bronze will 
resist the action of most acids used in manufactur- 
ing processes and this material should be kept in 
mind by plumbers, not only for use in connection 
with steam water heaters, but for any other pur- 
pose found useful for in the calling. 

It must be borne in mind that only good, pure, 
live steam is suitable for heating water by direct 
contact. Steam which has been used expansively 
in engines, pumps or other apparatus is not suit- 
able for the purpose. The reason for this lies in 
the fact that cylinder oils and other lubricants 
used around machinery come in contact with the 
steam passing through the cylinders and if the 
steam becomes saturated or charged with oil, as it 
very likely will, the oil would form on the surface 
of water in the tank, and attach itself to anything 
which was put in or taken out of the water. Be- 
sides, for many industrial purposes, the taste of oil 
in the water used would spoil the article. For 
instance, if string beans or peas were being boiled 
in open vessels by means of steam in direct con- 
tact with the water, the oil in the steam would 



114 Hot Water for Domestic Use 

flavor the vegetables and render them unfit for 
canning. If on the other hand it were clothes that 
were being boiled, a deposit of oil on the fabrics 
might do great injury to them. For these reasons 
when heating water with steam in direct contact, 
only pure live steam should be employed. 

A serious drawback to the use of steam for 
heating water by direct contact is due to the fact 
that when the steam is brought into contact with 
water in an open vessel it causes a loud rattling 
hammering noise, which drowns the sound of 
everything else nearby. This is caused by the 
steam bubbles which when they escape from the 
perforations start toward the surface, where, if 
they reach it, they collapse with a report. If, how- 
ever, the water is very cold, the bubbles of steam 
are condensed or collapsed almost as soon as they 
come in contact with the water and the water rush- 
ing in to fill the vacuum caused by the collapse of 
the bubble, causes a report like the muffled dis- 
charge of a gun. For this reason, water is heated 
with steam in direct contact through perforated 
pipes, only when noise is not objectionable. 

If a slight noise is not objectionable and the 
method adopted to overcome it is not objectionable 
for other reasons, water may still be heated by 
steam in direct contact, discharged through a per- 
forated pipe. If, after the perforated pipe is set in 
place, the bottom of the tank to above the level of 



Steam Required 115 

the pipe be covered with clean pebbles about the 
size of peas, there will be a noise when the steam 
is turned on, but it will not be so loud or annoy- 
ing as when the pebbles are not used. The reasons 
for this are twofold. In the first place, the pres- 
ence of the pebbles breaks up the steam bubbles 
into smaller sizes so that when they do collapse 
the collapsing bubbles are small and consequently 
have a mild report. In the second place the water 
cannot rush together so readily to fill the vacuum 
caused by the collapsing bubble and the more grad- 
ually the water comes together, the lighter will be 
the report. 

When calculating the amount of steam which 
will be required to heat water by direct contact, a 
simple rule which will be found approximately cor- 
rect, is to allow I pound of steam for each gallon 
of water to be heated. This is assuming that the 
water is no colder than 60 degrees Fahrenheit, and 
that the temperature need not be raised more than 
180 degrees or 190 degrees Fahrenheit. If water 
must be heated to the boiling point an allowance of 
perhaps 1J/2 pounds of steam for each gallon of 
water will be found more nearly correct. A feat- 
ure of heating water with steam in direct contact, 
which must not be overlooked, is the fact that the 
volume of water in the tank is thereby increased. 
This would naturally follow on account of the 
steam being discharged into the water. The al- 



116 Hot Water for Domestic Use 

lowance which must be made for this increase can 
be easily calculated when the quantity of water to 
be heated is known and the tank can be propor- 
tioned accordingly. When one pound of steam is 
condensed to water, the water, of course, will weigh 
as much as the steam did. That being true, for 
each pound of steam added to the water, the water 
would be increased in weight one pound, and as 
one pound of steam will be added to the tank for 
each gallon of water heated, all that will be neces- 
sary to find the total amount will be to divide the 
quantity of water to be heated by 8.33 which is 
the weight of one gallon of water and the quotient 
will be the number of gallons of water condensed 
from the steam which will be added to the water 
in the tank. 

Heating Water With Steam Nozzles. 

A nozzle for heating water, noiselessly, by means 
of steam in direct contact, is shown in perspective 
in Fig. 24. It consists simply of an outward and 
upward discharging steam nozzle, covered with a 
shield which has nimierous openings for the ad- 
mission of water so that the jet takes the form of 
an inverted cone, discharging upwards. To make 
the operation of the apparatus noiseless, air is ad- 
mitted through a small pipe and drawn in by the 
jet. By mixing with the steam this air prevents the 
sudden collapse of bubbles, and the consequent 



Quieting the Noise 



117 



noise which is such a great objection to heating by 
direct steam in the old way. A valve or stop cock 
should be placed on the air pipe so the supply of 
air can be regulated to the quantity most desirable. 
When water is to be heated to a less tempera- 
ture than 165 degrees Fahrenheit and that tem- 
perature is sufficient for all domestic purposes, the 




W — HT 



Fig. 24. Shows a nozzle for heating water noiselessly by 
means of steam in direct contact with the water. 

air pipe need not be used, as the heater will oper- 
ate noiselessly without it. If however, the tem- 
perature of the water must be raised above 165 
degrees Fahrenheit, the air pipe should be used. 
When the pressure of steam is sufficient, air need 
not be delivered to the nozzle under pressure. 
When however, the steam pressure is low the air 
must also be delivered under pressure to insure the 
noiseless operation of the apparatus. 



Index 119 



INDEX 

A 
Amount of Heating Surface Required in Steam 

Coil for Heating Water in a tank 110 

Automatic Control for Gas Water Heaters 87 

Automatic Instantaneous Water Heaters 88-95 

B 

Benedict Nickel Tubing for Range Boiler Piping. . 29 

Boiling Points of Water 40 

Brass Pipe for Range Boiler Connections 32 

Brass Tubes for Range Boiler Piping 29 

British Thermal Unit, What it is 11 

Bursting of Water Backs, Cause of 51 

C 

Capacity of Gas Water Heaters 80 

Check Valves for Cold Water Supply 38 

Check Valves, Use of 33 

Cold Water Supply to Kitchen Range Boiler 27 

Conducting Properties of Metals and Alloys 21 

Conduction of Heat 18 

Connections for Range Boilers 24 

Connections to Water Heaters 65 

Copper Pipe for Range Boiler Connections 32 

Copper Tubes for Range Boiler Piping 29 

D 

Density of Water at Different Temperatures 36 

Difference Between Temperature and Heat 10 

B 

Emptying Cock for Range Boiler 26 

Exhaust Steam, Heating Water with 107 

Expansion of Water 7 

Expansion Pipe, How it is Installed 35 

Expansion Pipe, Its Function 35 

P 
Prictional Resistance of Flow from Roughness of 

Interior Walls of Pipe 17 



120 Hot Water for Domestic Use 

G 

Garbage Burning Water Heaters 67 

Garnot's Explanation of Heat Conduction 18 

Gas a Fuel for Water Heaters 68 

Gas Heaters Must Be Vented 79 

Gas Supply to Water Heaters 78 

Gas Water Heaters Attached to Range Boilers. ... 69, 70 

Gasoline as Fuel for Hot Water Heaters 76 

Grate Surface of Water Heaters 65 

Ground-Key Stop-Cock for Gas Water Heaters.... 77 

H 

Heat and Temperature, Difference Between 10 

Heat Conduction, Garnot's Explanation of 18 

Heating Large Bodies of Water 86 

Heating Water by Pipe Coils 62, 63 

Heating Water with Ex:haust Steam 107 

Heating Water with Gas 68 

Heaing Water with Live Steam 104 

Heating Water by Kitchen Ranges 49 

Heating Water with Steam in Contact 110-116 

Heating Water with Steam Nozzles 116, 117 

Hot Water in Circulation, Velocity of Flow 16 

How to Connect Cold Water Pipe to Kitchen Range 

Boiler 80 

How to Connect Hot Water Pipe to Kitchen Range 

Boiler 80 

How to Determine Pressure of Water 45 

How to Measure Heat 11 

How Gas is Supplied to Instantaneous Water 

Heaters 75 

How to Install Instantaneous Water Heaters 70,71 

How Steam is Brought in Contact with Water. . .111, 112 

I 

Incrustation of Water Backs 55 

Instantaneous Automatic Water Heaters, Interior 

Construction of 90 

Instantaneous Water Heaters 69-77 

Instantaneous Water Heaters, Automatic 88-95 

Instantaneous Water Heaters, How They Operate 71-72 

Iron Pipe for Range Boiler Connections 32 



Index 121 

K 

Kitchen Range Boiler Connections 24 

Kitchen Range Boiler Connections, Materials for. . 32 
Kitchen Range Boilers, Steam Connections to. ... 101-104 

L 

Latent Heat, What it is 13 

Lift Check Valves 38 

Live Steam for Heating Water 104 

Live Steam, How it is Circulated in Coils 106 

Local Circulation of Water 8 

M 

Materials for Perforated Pipe for Heating Water 

with Steam 113 

Multiple Gas Water Heaters 86-88 

Materials for Range-Boiler Connections 32 

Materials for Steam Coils for Hot Water Tanks.. 110 

Measuring Heat, How it is Done 11 

Metals and Alloys, Heat Conductivity of 21 

Mud, Deposits of, in Water Backs and Boilers 60-62 

N 
Noise from Steam in Contact with Water, How to 

Avoid it 114-115 

Non-Conducting Materials, Relative Value of 22 

O 

Operation of Instantaneous Automatic Water 

Heaters 91 

Operation of Thermostats 83 

P 

Pipe Coils for Heating Water 62-63 

Pressures and Temperatures of Boiling Water 41,42 

Pressure of Boiling Water 41 

Pressure of Water at Various Temperatures 41-47 

Preventing Incrustation of Water Backs, How to 

do it 55-59 

Principle of Heating Water in a Range Boiler 23 

Principles, Hot Water Circulation 7 

R 

Range-Boiler Connections 24 

Range-Boiler Connections, Materials For 32 

Range-Boilers, Steam Connections to 101-104 



122 Hot Water for Domestic Use 

s 

Safety Valves 39 

Safety Valves, Use of 33 

Sensible Heat, What it is 13 

Smoke Flue for Water Heater 66 

Special Gas Water Heaters 81-85 

Special Water Heaters 64 

Steam, Amount of, Required to Heat Water by 

Direct Contact 115 

Steam Nozzles, Heating Water with 116-117 

Steam Connections to Range-Boilers 101-104 

Steam, Saturated, Properties of 97-99 

Storage Tank for Hot Water Supply 108 

Swing Check Valves 38 

T 

Tank for Storing Hot Water Supply 108 

Temperature and Heat, Difference Between 10 

Thermometers 20 

Thermostatic Valve for Gas Water Heaters 87 

Thermostats, They Operate !^3 

Transmission of Heat to Water 45 

U 

Unit of Heat 11 

Use of Steam for Heating Water 96 

V 

Valves, Check, for Cold Water Supply 38 

Velocity of Flow of Hot Water in Circulation 16 

W 

Water Back 52 

Water Back, Sectional View of 50 

Water Backs, Incrustation of 55 

Water Circulation, Cause of 8 

Water Circulation in Circuit 14 

Water Heaters, Connections to 65 

Water Heaters, Garbage Burning 67- 

Water Heaters, Special 64 

Water, How it is Heated by Steam 96 

Wrought Iron Pipe for Range Boiler Connections.. 29 



Notes on Heating and Ventilation. 




By John R. Allen, C. E., 
Junior Professor of Mechan- 
ical Engineering, University 
of Michigan, Mem. Am. Soc. 
Heating and Ventilating En- 
gineers, etc. Second enlarged 
edition. This book is a 
resume of lectures delivered 
to classes in heating and ven- 
tilation at the University of 
Michigan. It is written pri- 
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and designer of heating sys- 
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inches ; 272 pp. ; postpaid, $2. 



Sizes of Flow and Return Steam 
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Contributions from thirty 
heating engineers of dif- 
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Bound in boards, 6% x 4j4 
inches, 104 pp.; postpaid, 
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DOMESTIC ENGINEERING CO. 

32S Dearborn Street CHICAGO, ILUNOIS 



Plumbing Catechism. 



ijiipLUMllll! 

mtcm 



By C. B. Ball, Chief Sani- 
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"Domestic Engineering." 

This book formulates, 
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Bound in cloth; 6^4x4 J^ 
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Sanitation in the Modern Home. 

By Jno. K. Allen, Assoc. 
Mem. Am. Society Heating 
and Ventilating Engineers. 

A really invaluable 
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DOMESTIC ENGINEERING CO. 

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Roughing-in House Drains. 

Edited by Jno. K. Al- 
len. A complete guide to 
the work of roughing-in 
plumbing, from the dig- 
ging of the sewer to the 
finishing length of the 
house drain, giving each 
step to be taken and telling 
how and why it is done. 
88 illustrations. 6j4x4j4 
inches; 184 pp.; bound in 
boards; postpaid, 50 cents. 




The Sanitary Sewerage of 
Buildings. 



By Thos. S. Ainge, a lead- 
ing authority. A complete 
and comprehensive discussion 
of the subject. Practical and 
plain, profusely illustrated 
with diagrams and drawings. 
Explains general principles 
of sewerage and details of 
sewer construction. Bound in 
cloth, 222 pp.; price post- 
paid, $1.50. 



jnitary. 



Build'"' 



DOMESTIC ENGINEERING CO. 

325 Dearborn Street ^ CHICAGO. ILUNOIS 




Swimming Pools. 

By Jno. K. Allen, 
member Am. Soc. Inspec- 
tors of Plumbing and Sani-* 
tary Engineers ; Assoc. 
Mem. Am. Soc. of Heat- 
ing and Ventilating En- 
gineers. A complete man- 
ual on Swimming Pools; 
their construction; cold 
and hot water supply; 
various methods of 
heating the water; direc- 
tions as to selecting cor- 
rect sizes of heaters. Over 
thirty illustrations. Post- 
paid, 50 ^'^nts. 

A Complete Guide to Testing 
Plumbing. 

By Jno. K. Allen, Mem. 
Am. Soc. Inspectors of 
Plumbing and Sanitary 
Engineers. A full treatise 
showing the necessity of 
testing new and old work; 
methods of testing fully de- 
scribed, seventeen illustra- 
tions ; postpaid, 25 cents. 




DOMESTIC ENGINEERING CO. 

325 Dearborn Street CHICAGO. ILLINOIS 



1 



FEB 18 1911 



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